Do not use double-quotes on strings that do not need interpolation

Using double-quotes imposes a small performance penalty as the perl
parser needs to check if any interpolation is needed. Use double-quotes
only when the string contains single-quotes. Ideally we'd use
double-quotes too for escaped meta-characters that might otherwise be
confusing to immediately see if they need interpolation or not, but the
policy does not (currently) allow to ignore these.

Fixes ValuesAndExpressions::ProhibitInterpolationOfLiterals.

Warned-by: perlcritic

7 files changed, 237 insertions, 237 deletions

diff --git a/scripts/Dpkg/Source/Package/V1.pm b/scripts/Dpkg/Source/Package/V1.pm
index 314ae0f16..a8829e9a0 100644
--- a/scripts/Dpkg/Source/Package/V1.pm
+++ b/scripts/Dpkg/Source/Package/V1.pm
@@ -18,7 +18,7 @@ package Dpkg::Source::Package::V1;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 use base 'Dpkg::Source::Package';
 
@@ -38,7 +38,7 @@ use File::Basename;
 use File::Temp qw(tempfile);
 use File::Spec;
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub init_options {
     my ($self) = @_;
@@ -49,8 +49,8 @@ sub init_options {
     } else {
 	$self->{options}{diff_ignore_regexp} = '(?:^|/)debian/source/local-.*$';
     }
-    push @{$self->{options}{tar_ignore}}, "debian/source/local-options",
-         "debian/source/local-patch-header";
+    push @{$self->{options}{tar_ignore}}, 'debian/source/local-options',
+         'debian/source/local-patch-header';
     $self->{options}{sourcestyle} ||= 'X';
     $self->{options}{skip_debianization} ||= 0;
     $self->{options}{abort_on_upstream_changes} ||= 0;
@@ -60,7 +60,7 @@ sub parse_cmdline_option {
     my ($self, $opt) = @_;
     my $o = $self->{options};
     if ($opt =~ m/^-s([akpursnAKPUR])$/) {
-        warning(_g("-s%s option overrides earlier -s%s option"), $1,
+        warning(_g('-s%s option overrides earlier -s%s option'), $1,
                 $o->{sourcestyle}) if $o->{sourcestyle} ne 'X';
         $o->{sourcestyle} = $1;
         $o->{copy_orig_tarballs} = 0 if $1 eq 'n'; # Extract option -sn
@@ -82,7 +82,7 @@ sub do_extract {
 
     $sourcestyle =~ y/X/p/;
     $sourcestyle =~ m/[pun]/ ||
-	usageerr(_g("source handling style -s%s not allowed with -x"),
+	usageerr(_g('source handling style -s%s not allowed with -x'),
 	         $sourcestyle);
 
     my $dscdir = $self->{basedir};
@@ -94,20 +94,20 @@ sub do_extract {
     my ($tarfile, $difffile);
     foreach my $file ($self->get_files()) {
 	if ($file =~ /^(?:\Q$basename\E\.orig|\Q$basenamerev\E)\.tar\.gz$/) {
-            error(_g("multiple tarfiles in v1.0 source package")) if $tarfile;
+            error(_g('multiple tarfiles in v1.0 source package')) if $tarfile;
             $tarfile = $file;
 	} elsif ($file =~ /^\Q$basenamerev\E\.diff\.gz$/) {
 	    $difffile = $file;
 	} else {
-	    error(_g("unrecognized file for a %s source package: %s"),
-                  "v1.0", $file);
+	    error(_g('unrecognized file for a %s source package: %s'),
+                  'v1.0', $file);
 	}
     }
 
-    error(_g("no tarfile in Files field")) unless $tarfile;
+    error(_g('no tarfile in Files field')) unless $tarfile;
     my $native = $difffile ? 0 : 1;
     if ($native and ($tarfile =~ /\.orig\.tar\.gz$/)) {
-        warning(_g("native package with .orig.tar"));
+        warning(_g('native package with .orig.tar'));
         $native = 0; # V3::native doesn't handle orig.tar
     }
 
@@ -124,39 +124,39 @@ sub do_extract {
                            "$newdirectory.tmp-keep");
         }
 
-        info(_g("unpacking %s"), $tarfile);
+        info(_g('unpacking %s'), $tarfile);
         my $tar = Dpkg::Source::Archive->new(filename => "$dscdir$tarfile");
         $tar->extract($expectprefix);
 
         if ($sourcestyle =~ /u/) {
             # -su: keep .orig directory unpacked
             if (-e "$newdirectory.tmp-keep") {
-                error(_g("unable to keep orig directory (already exists)"));
+                error(_g('unable to keep orig directory (already exists)'));
             }
             system('cp', '-ar', '--', $expectprefix, "$newdirectory.tmp-keep");
             subprocerr("cp $expectprefix to $newdirectory.tmp-keep") if $?;
         }
 
 	rename($expectprefix, $newdirectory) ||
-	    syserr(_g("failed to rename newly-extracted %s to %s"),
+	    syserr(_g('failed to rename newly-extracted %s to %s'),
 	           $expectprefix, $newdirectory);
 
 	# rename the copied .orig directory
 	if (-e "$newdirectory.tmp-keep") {
 	    rename("$newdirectory.tmp-keep", $expectprefix) ||
-                    syserr(_g("failed to rename saved %s to %s"),
+                    syserr(_g('failed to rename saved %s to %s'),
 	                   "$newdirectory.tmp-keep", $expectprefix);
         }
     }
 
     if ($difffile and not $self->{options}{skip_debianization}) {
         my $patch = "$dscdir$difffile";
-	info(_g("applying %s"), $difffile);
+	info(_g('applying %s'), $difffile);
 	my $patch_obj = Dpkg::Source::Patch->new(filename => $patch);
 	my $analysis = $patch_obj->apply($newdirectory, force_timestamp => 1);
 	my @files = grep { ! m{^\Q$newdirectory\E/debian/} }
 		    sort keys %{$analysis->{filepatched}};
-	info(_g("upstream files that have been modified: %s"),
+	info(_g('upstream files that have been modified: %s'),
 	     "\n " . join("\n ", @files)) if scalar @files;
     }
 }
@@ -165,8 +165,8 @@ sub can_build {
     my ($self, $dir) = @_;
     # As long as we can use gzip, we can do it as we have
     # native packages as fallback
-    return ($self->{options}{compression} eq "gzip",
-            _g("only supports gzip compression"));
+    return ($self->{options}{compression} eq 'gzip',
+            _g('only supports gzip compression'));
 }
 
 sub do_build {
@@ -177,13 +177,13 @@ sub do_build {
     my $diff_ignore_regexp = $self->{options}{diff_ignore_regexp};
 
     if (scalar(@argv) > 1) {
-        usageerr(_g("-b takes at most a directory and an orig source ".
-                    "argument (with v1.0 source package)"));
+        usageerr(_g('-b takes at most a directory and an orig source ' .
+                    'argument (with v1.0 source package)'));
     }
 
     $sourcestyle =~ y/X/A/;
     unless ($sourcestyle =~ m/[akpursnAKPUR]/) {
-        usageerr(_g("source handling style -s%s not allowed with -b"),
+        usageerr(_g('source handling style -s%s not allowed with -b'),
                  $sourcestyle);
     }
 
@@ -195,7 +195,7 @@ sub do_build {
 
     # Try to find a .orig tarball for the package
     my $origdir = "$dir.orig";
-    my $origtargz = $self->get_basename() . ".orig.tar.gz";
+    my $origtargz = $self->get_basename() . '.orig.tar.gz';
     if (-e $origtargz) {
         unless (-f $origtargz) {
             error(_g("packed orig `%s' exists but is not a plain file"), $origtargz);
@@ -210,33 +210,33 @@ sub do_build {
         my $origarg = shift(@argv);
         if (length($origarg)) {
             stat($origarg) ||
-                syserr(_g("cannot stat orig argument %s"), $origarg);
+                syserr(_g('cannot stat orig argument %s'), $origarg);
             if (-d _) {
                 $origdir = File::Spec->catdir($origarg);
 
                 $sourcestyle =~ y/aA/rR/;
                 unless ($sourcestyle =~ m/[ursURS]/) {
-                    error(_g("orig argument is unpacked but source handling " .
-                             "style -s%s calls for packed (.orig.tar.<ext>)"),
+                    error(_g('orig argument is unpacked but source handling ' .
+                             'style -s%s calls for packed (.orig.tar.<ext>)'),
                           $sourcestyle);
                 }
             } elsif (-f _) {
                 $origtargz = $origarg;
                 $sourcestyle =~ y/aA/pP/;
                 unless ($sourcestyle =~ m/[kpsKPS]/) {
-                    error(_g("orig argument is packed but source handling " .
-                             "style -s%s calls for unpacked (.orig/)"),
+                    error(_g('orig argument is packed but source handling ' .
+                             'style -s%s calls for unpacked (.orig/)'),
                           $sourcestyle);
                 }
             } else {
-                error(_g("orig argument %s is not a plain file or directory"),
+                error(_g('orig argument %s is not a plain file or directory'),
                       $origarg);
             }
         } else {
             $sourcestyle =~ y/aA/nn/;
             $sourcestyle =~ m/n/ ||
-                error(_g("orig argument is empty (means no orig, no diff) " .
-                         "but source handling style -s%s wants something"),
+                error(_g('orig argument is empty (means no orig, no diff) ' .
+                         'but source handling style -s%s wants something'),
                       $sourcestyle);
         }
     } elsif ($sourcestyle =~ m/[aA]/) {
@@ -271,8 +271,8 @@ sub do_build {
 	my ($origdirname, $origdirbase) = fileparse($origdir);
 
         if ($origdirname ne "$basedirname.orig") {
-            warning(_g(".orig directory name %s is not <package>" .
-	               "-<upstreamversion> (wanted %s)"),
+            warning(_g('.orig directory name %s is not <package>' .
+	               '-<upstreamversion> (wanted %s)'),
 	            $origdirname, "$basedirname.orig");
         }
         $tardirbase = $origdirbase;
@@ -280,26 +280,26 @@ sub do_build {
 
 	$tarname = $origtargz || "$basename.orig.tar.gz";
 	unless ($tarname =~ /\Q$basename\E\.orig\.tar\.gz/) {
-	    warning(_g(".orig.tar name %s is not <package>_<upstreamversion>" .
-	               ".orig.tar (wanted %s)"),
+	    warning(_g('.orig.tar name %s is not <package>_<upstreamversion>' .
+	               '.orig.tar (wanted %s)'),
 	            $tarname, "$basename.orig.tar.gz");
 	}
     }
 
-    if ($sourcestyle eq "n") {
+    if ($sourcestyle eq 'n') {
         $self->{options}{ARGV} = []; # ensure we have no error
         Dpkg::Source::Package::V3::native::do_build($self, $dir);
     } elsif ($sourcestyle =~ m/[nurUR]/) {
         if (stat($tarname)) {
             unless ($sourcestyle =~ m/[nUR]/) {
 		error(_g("tarfile `%s' already exists, not overwriting, " .
-		         "giving up; use -sU or -sR to override"), $tarname);
+		         'giving up; use -sU or -sR to override'), $tarname);
             }
         } elsif ($! != ENOENT) {
 	    syserr(_g("unable to check for existence of `%s'"), $tarname);
         }
 
-	info(_g("building %s in %s"),
+	info(_g('building %s in %s'),
 	     $sourcepackage, $tarname);
 
 	my ($ntfh, $newtar) = tempfile("$tarname.new.XXXXXX",
@@ -316,7 +316,7 @@ sub do_build {
 	chmod(0666 &~ umask(), $tarname) ||
 	    syserr(_g("unable to change permission of `%s'"), $tarname);
     } else {
-	info(_g("building %s using existing %s"),
+	info(_g('building %s using existing %s'),
 	     $sourcepackage, $tarname);
     }
 
@@ -326,7 +326,7 @@ sub do_build {
         if (stat($origdir)) {
             unless ($sourcestyle =~ m/[KP]/) {
                 error(_g("orig dir `%s' already exists, not overwriting, ".
-                         "giving up; use -sA, -sK or -sP to override"),
+                         'giving up; use -sA, -sK or -sP to override'),
                       $origdir);
             }
 	    push @Dpkg::Exit::handlers, sub { erasedir($origdir) };
@@ -344,13 +344,13 @@ sub do_build {
     my $ur; # Unrepresentable changes
     if ($sourcestyle =~ m/[kpursKPUR]/) {
 	my $diffname = "$basenamerev.diff.gz";
-	info(_g("building %s in %s"),
+	info(_g('building %s in %s'),
 	     $sourcepackage, $diffname);
 	my ($ndfh, $newdiffgz) = tempfile("$diffname.new.XXXXXX",
 					DIR => getcwd(), UNLINK => 0);
         push @Dpkg::Exit::handlers, sub { unlink($newdiffgz) };
         my $diff = Dpkg::Source::Patch->new(filename => $newdiffgz,
-                                            compression => "gzip");
+                                            compression => 'gzip');
         $diff->create();
         $diff->add_diff_directory($origdir, $dir,
                 basedirname => $basedirname,
@@ -364,11 +364,11 @@ sub do_build {
 	my @files = grep { ! m{^debian/} } map { s{^[^/]+/+}{}; $_ }
 		    sort keys %{$analysis->{filepatched}};
 	if (scalar @files) {
-	    warning(_g("the diff modifies the following upstream files: %s"),
+	    warning(_g('the diff modifies the following upstream files: %s'),
 	            "\n " . join("\n ", @files));
 	    info(_g("use the '3.0 (quilt)' format to have separate and " .
-	            "documented changes to upstream files, see dpkg-source(1)"));
-	    error(_g("aborting due to --abort-on-upstream-changes"))
+	            'documented changes to upstream files, see dpkg-source(1)'));
+	    error(_g('aborting due to --abort-on-upstream-changes'))
 		if $self->{options}{abort_on_upstream_changes};
 	}
 
@@ -386,7 +386,7 @@ sub do_build {
     }
 
     if ($ur) {
-        printf(STDERR _g("%s: unrepresentable changes to source")."\n",
+        printf(STDERR _g('%s: unrepresentable changes to source') . "\n",
                $progname);
         exit(1);
     }
diff --git a/scripts/Dpkg/Source/Package/V2.pm b/scripts/Dpkg/Source/Package/V2.pm
index 4da8bdae2..be1d363a7 100644
--- a/scripts/Dpkg/Source/Package/V2.pm
+++ b/scripts/Dpkg/Source/Package/V2.pm
@@ -18,7 +18,7 @@ package Dpkg::Source::Package::V2;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 use base 'Dpkg::Source::Package';
 
@@ -43,7 +43,7 @@ use File::Spec;
 use File::Find;
 use File::Copy;
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub init_options {
     my ($self) = @_;
@@ -120,7 +120,7 @@ sub do_extract {
     my $re_ext = $compression_re_file_ext;
     foreach my $file ($self->get_files()) {
         (my $uncompressed = $file) =~ s/\.$re_ext$//;
-        error(_g("duplicate files in %s source package: %s.*"), "v2.0",
+        error(_g('duplicate files in %s source package: %s.*'), 'v2.0',
               $uncompressed) if $seen{$uncompressed};
         $seen{$uncompressed} = 1;
         if ($file =~ /^\Q$basename\E\.orig\.tar\.$re_ext$/) {
@@ -130,23 +130,23 @@ sub do_extract {
         } elsif ($file =~ /^\Q$basenamerev\E\.debian\.tar\.$re_ext$/) {
             $debianfile = $file;
         } else {
-            error(_g("unrecognized file for a %s source package: %s"),
-            "v2.0", $file);
+            error(_g('unrecognized file for a %s source package: %s'),
+            'v2.0', $file);
         }
     }
 
     unless ($tarfile and $debianfile) {
-        error(_g("missing orig.tar or debian.tar file in v2.0 source package"));
+        error(_g('missing orig.tar or debian.tar file in v2.0 source package'));
     }
 
     erasedir($newdirectory);
 
     # Extract main tarball
-    info(_g("unpacking %s"), $tarfile);
+    info(_g('unpacking %s'), $tarfile);
     my $tar = Dpkg::Source::Archive->new(filename => "$dscdir$tarfile");
     $tar->extract($newdirectory, no_fixperms => 1,
-                  options => [ "--anchored", "--no-wildcards-match-slash",
-                               "--exclude", "*/.pc", "--exclude", ".pc" ]);
+                  options => [ '--anchored', '--no-wildcards-match-slash',
+                               '--exclude', '*/.pc', '--exclude', '.pc' ]);
     # The .pc exclusion is only needed for 3.0 (quilt) and to avoid
     # having an upstream tarball provide a directory with symlinks
     # that would be blindly followed when applying the patches
@@ -154,7 +154,7 @@ sub do_extract {
     # Extract additional orig tarballs
     foreach my $subdir (keys %origtar) {
         my $file = $origtar{$subdir};
-        info(_g("unpacking %s"), $file);
+        info(_g('unpacking %s'), $file);
         if (-e "$newdirectory/$subdir") {
             warning(_g("required removal of `%s' installed by original tarball"), $subdir);
             erasedir("$newdirectory/$subdir");
@@ -167,7 +167,7 @@ sub do_extract {
     return if $self->{options}{skip_debianization};
 
     # Extract debian tarball after removing the debian directory
-    info(_g("unpacking %s"), $debianfile);
+    info(_g('unpacking %s'), $debianfile);
     erasedir("$newdirectory/debian");
     # Exclude existing symlinks from extraction of debian.tar.gz as we
     # don't want to overwrite something outside of $newdirectory due to a
@@ -176,7 +176,7 @@ sub do_extract {
     my $wanted = sub {
         return if not -l $_;
         my $fn = File::Spec->abs2rel($_, $newdirectory);
-        push @exclude_symlinks, "--exclude", $fn;
+        push @exclude_symlinks, '--exclude', $fn;
     };
     find({ wanted => $wanted, no_chdir => 1 }, $newdirectory);
     $tar = Dpkg::Source::Archive->new(filename => "$dscdir$debianfile");
@@ -190,7 +190,7 @@ sub do_extract {
 }
 
 sub get_autopatch_name {
-    return "zz_debian-diff-auto";
+    return 'zz_debian-diff-auto';
 }
 
 sub get_patches {
@@ -200,7 +200,7 @@ sub get_patches {
     my $pd = "$dir/debian/patches";
     my $auto_patch = $self->get_autopatch_name();
     if (-d $pd) {
-        opendir(my $dir_dh, $pd) || syserr(_g("cannot opendir %s"), $pd);
+        opendir(my $dir_dh, $pd) || syserr(_g('cannot opendir %s'), $pd);
         foreach my $patch (sort readdir($dir_dh)) {
             # patches match same rules as run-parts
             next unless $patch =~ /^[\w-]+$/ and -f "$pd/$patch";
@@ -217,14 +217,14 @@ sub apply_patches {
     $opts{skip_auto} //= 0;
     my @patches = $self->get_patches($dir, %opts);
     return unless scalar(@patches);
-    my $applied = File::Spec->catfile($dir, "debian", "patches", ".dpkg-source-applied");
+    my $applied = File::Spec->catfile($dir, 'debian', 'patches', '.dpkg-source-applied');
     open(my $applied_fh, '>', $applied) ||
-        syserr(_g("cannot write %s"), $applied);
+        syserr(_g('cannot write %s'), $applied);
     print $applied_fh "# During $opts{usage}\n";
     my $timestamp = fs_time($applied);
     foreach my $patch ($self->get_patches($dir, %opts)) {
-        my $path = File::Spec->catfile($dir, "debian", "patches", $patch);
-        info(_g("applying %s"), $patch) unless $opts{skip_auto};
+        my $path = File::Spec->catfile($dir, 'debian', 'patches', $patch);
+        info(_g('applying %s'), $patch) unless $opts{skip_auto};
         my $patch_obj = Dpkg::Source::Patch->new(filename => $path);
         $patch_obj->apply($dir, force_timestamp => 1,
                           timestamp => $timestamp,
@@ -238,11 +238,11 @@ sub unapply_patches {
     my ($self, $dir, %opts) = @_;
     my @patches = reverse($self->get_patches($dir, %opts));
     return unless scalar(@patches);
-    my $applied = File::Spec->catfile($dir, "debian", "patches", ".dpkg-source-applied");
+    my $applied = File::Spec->catfile($dir, 'debian', 'patches', '.dpkg-source-applied');
     my $timestamp = fs_time($applied);
     foreach my $patch (@patches) {
-        my $path = File::Spec->catfile($dir, "debian", "patches", $patch);
-        info(_g("unapplying %s"), $patch) unless $opts{quiet};
+        my $path = File::Spec->catfile($dir, 'debian', 'patches', $patch);
+        info(_g('unapplying %s'), $patch) unless $opts{quiet};
         my $patch_obj = Dpkg::Source::Patch->new(filename => $path);
         $patch_obj->apply($dir, force_timestamp => 1, verbose => 0,
                           timestamp => $timestamp,
@@ -253,11 +253,11 @@ sub unapply_patches {
 
 sub upstream_tarball_template {
     my ($self) = @_;
-    my $ext = "{" . join(",",
+    my $ext = '{' . join(',',
         sort map {
-            compression_get_property($_, "file_ext")
-        } compression_get_list()) . "}";
-    return "../" . $self->get_basename() . ".orig.tar.$ext";
+            compression_get_property($_, 'file_ext')
+        } compression_get_list()) . '}';
+    return '../' . $self->get_basename() . ".orig.tar.$ext";
 }
 
 sub can_build {
@@ -265,7 +265,7 @@ sub can_build {
     return 1 if $self->find_original_tarballs(include_supplementary => 0);
     return 1 if $self->{options}{create_empty_orig} and
                 $self->find_original_tarballs(include_main => 0);
-    return (0, sprintf(_g("no upstream tarball found at %s"),
+    return (0, sprintf(_g('no upstream tarball found at %s'),
                        $self->upstream_tarball_template()));
 }
 
@@ -276,17 +276,17 @@ sub before_build {
 
 sub after_build {
     my ($self, $dir) = @_;
-    my $applied = File::Spec->catfile($dir, "debian", "patches", ".dpkg-source-applied");
-    my $reason = "";
+    my $applied = File::Spec->catfile($dir, 'debian', 'patches', '.dpkg-source-applied');
+    my $reason = '';
     if (-e $applied) {
-        open(my $applied_fh, "<", $applied) ||
-            syserr(_g("cannot read %s"), $applied);
+        open(my $applied_fh, '<', $applied) ||
+            syserr(_g('cannot read %s'), $applied);
         $reason = <$applied_fh>;
         close($applied_fh);
     }
     my $opt_unapply = $self->{options}{unapply_patches};
-    if (($opt_unapply eq "auto" and $reason =~ /^# During preparation/) or
-        $opt_unapply eq "yes") {
+    if (($opt_unapply eq 'auto' and $reason =~ /^# During preparation/) or
+        $opt_unapply eq 'yes') {
         $self->unapply_patches($dir);
     }
 }
@@ -300,13 +300,13 @@ sub prepare_build {
         include_timestamp => $self->{options}{include_timestamp},
         use_dev_null => 1,
     };
-    push @{$self->{options}{tar_ignore}}, "debian/patches/.dpkg-source-applied";
+    push @{$self->{options}{tar_ignore}}, 'debian/patches/.dpkg-source-applied';
     $self->check_patches_applied($dir) if $self->{options}{preparation};
     if ($self->{options}{create_empty_orig} and
         not $self->find_original_tarballs(include_supplementary => 0))
     {
         # No main orig.tar, create a dummy one
-        my $filename = $self->get_basename() . ".orig.tar." .
+        my $filename = $self->get_basename() . '.orig.tar.' .
                        $self->{options}{comp_ext};
         my $tar = Dpkg::Source::Archive->new(filename => $filename);
         $tar->create();
@@ -316,9 +316,9 @@ sub prepare_build {
 
 sub check_patches_applied {
     my ($self, $dir) = @_;
-    my $applied = File::Spec->catfile($dir, "debian", "patches", ".dpkg-source-applied");
+    my $applied = File::Spec->catfile($dir, 'debian', 'patches', '.dpkg-source-applied');
     unless (-e $applied) {
-        info(_g("patches are not applied, applying them now"));
+        info(_g('patches are not applied, applying them now'));
         $self->apply_patches($dir, usage => 'preparation');
     }
 }
@@ -335,8 +335,8 @@ sub generate_patch {
     foreach (sort $self->find_original_tarballs()) {
         if (/\.orig\.tar\.$compression_re_file_ext$/) {
             if (defined($tarfile)) {
-                error(_g("several orig.tar files found (%s and %s) but only " .
-                         "one is allowed"), $tarfile, $_);
+                error(_g('several orig.tar files found (%s and %s) but only ' .
+                         'one is allowed'), $tarfile, $_);
             }
             $tarfile = $_;
             push @origtarballs, $_;
@@ -348,11 +348,11 @@ sub generate_patch {
         }
     }
 
-    error(_g("no upstream tarball found at %s"),
+    error(_g('no upstream tarball found at %s'),
           $self->upstream_tarball_template()) unless $tarfile;
 
-    if ($opts{usage} eq "build") {
-        info(_g("building %s using existing %s"),
+    if ($opts{usage} eq 'build') {
+        info(_g('building %s using existing %s'),
              $self->{fields}{'Source'}, "@origtarballs");
     }
 
@@ -373,19 +373,19 @@ sub generate_patch {
 
     # Copy over the debian directory
     erasedir("$tmp/debian");
-    system("cp", "-a", "--", "$dir/debian", "$tmp/");
-    subprocerr(_g("copy of the debian directory")) if $?;
+    system('cp', '-a', '--', "$dir/debian", "$tmp/");
+    subprocerr(_g('copy of the debian directory')) if $?;
 
     # Apply all patches except the last automatic one
     $opts{skip_auto} //= 0;
     $self->apply_patches($tmp, skip_auto => $opts{skip_auto}, usage => 'build');
 
     # Create a patch
-    my ($difffh, $tmpdiff) = tempfile($self->get_basename(1) . ".diff.XXXXXX",
+    my ($difffh, $tmpdiff) = tempfile($self->get_basename(1) . '.diff.XXXXXX',
                                       DIR => File::Spec->tmpdir(), UNLINK => 0);
     push @Dpkg::Exit::handlers, sub { unlink($tmpdiff) };
     my $diff = Dpkg::Source::Patch->new(filename => $tmpdiff,
-                                        compression => "none");
+                                        compression => 'none');
     $diff->create();
     if ($opts{header_from} and -e $opts{header_from}) {
         my $header_from = Dpkg::Source::Patch->new(
@@ -399,10 +399,10 @@ sub generate_patch {
             %{$self->{diff_options}},
             handle_binary_func => $opts{handle_binary},
             order_from => $opts{order_from});
-    error(_g("unrepresentable changes to source")) if not $diff->finish();
+    error(_g('unrepresentable changes to source')) if not $diff->finish();
 
     if (-s $tmpdiff) {
-        info(_g("local changes detected, the modified files are:"));
+        info(_g('local changes detected, the modified files are:'));
         my $analysis = $diff->analyze($dir, verbose => 0);
         foreach my $fn (sort keys %{$analysis->{filepatched}}) {
             print " $fn\n";
@@ -440,17 +440,17 @@ sub do_build {
             my $fn = File::Spec->abs2rel($_, $dir);
             $binaryfiles->new_binary_found($fn);
             unless ($include_binaries or $binaryfiles->binary_is_allowed($fn)) {
-                errormsg(_g("unwanted binary file: %s"), $fn);
+                errormsg(_g('unwanted binary file: %s'), $fn);
                 $unwanted_binaries++;
             }
         }
     };
-    my $tar_ignore_glob = "{" . join(",",
+    my $tar_ignore_glob = '{' . join(',',
         map {
             my $copy = $_;
             $copy =~ s/,/\\,/g;
             $copy;
-        } @{$self->{options}{tar_ignore}}) . "}";
+        } @{$self->{options}{tar_ignore}}) . '}';
     my $filter_ignore = sub {
         # Filter out files that are not going to be included in the debian
         # tarball due to ignores.
@@ -474,11 +474,11 @@ sub do_build {
         return @result;
     };
     find({ wanted => $check_binary, preprocess => $filter_ignore,
-           no_chdir => 1 }, File::Spec->catdir($dir, "debian"));
-    error(P_("detected %d unwanted binary file (add it in " .
-             "debian/source/include-binaries to allow its inclusion).",
-             "detected %d unwanted binary files (add them in " .
-             "debian/source/include-binaries to allow their inclusion).",
+           no_chdir => 1 }, File::Spec->catdir($dir, 'debian'));
+    error(P_('detected %d unwanted binary file (add it in ' .
+             'debian/source/include-binaries to allow its inclusion).',
+             'detected %d unwanted binary files (add them in ' .
+             'debian/source/include-binaries to allow their inclusion).',
              $unwanted_binaries), $unwanted_binaries)
          if $unwanted_binaries;
 
@@ -488,17 +488,17 @@ sub do_build {
         my $relfn = File::Spec->abs2rel($new, $dir);
         $binaryfiles->new_binary_found($relfn);
         unless ($include_binaries or $binaryfiles->binary_is_allowed($relfn)) {
-            errormsg(_g("cannot represent change to %s: %s"), $relfn,
-                     _g("binary file contents changed"));
-            errormsg(_g("add %s in debian/source/include-binaries if you want" .
-                     " to store the modified binary in the debian tarball"),
+            errormsg(_g('cannot represent change to %s: %s'), $relfn,
+                     _g('binary file contents changed'));
+            errormsg(_g('add %s in debian/source/include-binaries if you want ' .
+                        'to store the modified binary in the debian tarball'),
                      $relfn);
             $self->register_error();
         }
     };
 
     # Create a patch
-    my $autopatch = File::Spec->catfile($dir, "debian", "patches",
+    my $autopatch = File::Spec->catfile($dir, 'debian', 'patches',
                                         $self->get_autopatch_name());
     my $tmpdiff = $self->generate_patch($dir, order_from => $autopatch,
                                         header_from => $autopatch,
@@ -506,9 +506,9 @@ sub do_build {
                                         skip_auto => $self->{options}{auto_commit},
                                         usage => 'build');
     unless (-z $tmpdiff or $self->{options}{auto_commit}) {
-        info(_g("you can integrate the local changes with %s"),
-             "dpkg-source --commit");
-        error(_g("aborting due to unexpected upstream changes, see %s"),
+        info(_g('you can integrate the local changes with %s'),
+             'dpkg-source --commit');
+        error(_g('aborting due to unexpected upstream changes, see %s'),
               $tmpdiff);
     }
     push @Dpkg::Exit::handlers, sub { unlink($tmpdiff) };
@@ -516,22 +516,22 @@ sub do_build {
 
     # Install the diff as the new autopatch
     if ($self->{options}{auto_commit}) {
-        mkpath(File::Spec->catdir($dir, "debian", "patches"));
+        mkpath(File::Spec->catdir($dir, 'debian', 'patches'));
         $autopatch = $self->register_patch($dir, $tmpdiff,
                                            $self->get_autopatch_name());
-        info(_g("local changes have been recorded in a new patch: %s"),
+        info(_g('local changes have been recorded in a new patch: %s'),
              $autopatch) if -e $autopatch;
-        rmdir(File::Spec->catdir($dir, "debian", "patches")); # No check on purpose
+        rmdir(File::Spec->catdir($dir, 'debian', 'patches')); # No check on purpose
     }
-    unlink($tmpdiff) || syserr(_g("cannot remove %s"), $tmpdiff);
+    unlink($tmpdiff) || syserr(_g('cannot remove %s'), $tmpdiff);
     pop @Dpkg::Exit::handlers;
 
     # Create the debian.tar
     my $debianfile = "$basenamerev.debian.tar." . $self->{options}{comp_ext};
-    info(_g("building %s in %s"), $sourcepackage, $debianfile);
+    info(_g('building %s in %s'), $sourcepackage, $debianfile);
     my $tar = Dpkg::Source::Archive->new(filename => $debianfile);
     $tar->create(options => \@tar_ignore, chdir => $dir);
-    $tar->add_directory("debian");
+    $tar->add_directory('debian');
     foreach my $binary ($binaryfiles->get_seen_binaries()) {
         $tar->add_file($binary) unless $binary =~ m{^debian/};
     }
@@ -542,19 +542,19 @@ sub do_build {
 
 sub get_patch_header {
     my ($self, $dir) = @_;
-    my $ph = File::Spec->catfile($dir, "debian", "source", "local-patch-header");
+    my $ph = File::Spec->catfile($dir, 'debian', 'source', 'local-patch-header');
     unless (-f $ph) {
-        $ph = File::Spec->catfile($dir, "debian", "source", "patch-header");
+        $ph = File::Spec->catfile($dir, 'debian', 'source', 'patch-header');
     }
     my $text;
     if (-f $ph) {
-        open(my $ph_fh, "<", $ph) || syserr(_g("cannot read %s"), $ph);
-        $text = join("", <$ph_fh>);
+        open(my $ph_fh, '<', $ph) || syserr(_g('cannot read %s'), $ph);
+        $text = join('', <$ph_fh>);
         close($ph_fh);
         return $text;
     }
     my $ch_info = changelog_parse(offset => 0, count => 1,
-        file => File::Spec->catfile($dir, "debian", "changelog"));
+        file => File::Spec->catfile($dir, 'debian', 'changelog'));
     return '' if not defined $ch_info;
     my $header = Dpkg::Control->new(type => CTRL_UNKNOWN);
     $header->{'Description'} = "<short summary of the patch>\n";
@@ -567,7 +567,7 @@ it.\n";
     $header->{'Description'} .= $ch_info->{'Changes'} . "\n";
     $header->{'Author'} = $ch_info->{'Maintainer'};
     $text = "$header";
-    run_vendor_hook("extend-patch-header", \$text, $ch_info);
+    run_vendor_hook('extend-patch-header', \$text, $ch_info);
     $text .= "\n---
 The information above should follow the Patch Tagging Guidelines, please
 checkout http://dep.debian.net/deps/dep3/ to learn about the format. Here
@@ -585,19 +585,19 @@ Last-Update: <YYYY-MM-DD>\n\n";
 
 sub register_patch {
     my ($self, $dir, $patch_file, $patch_name) = @_;
-    my $patch = File::Spec->catfile($dir, "debian", "patches", $patch_name);
+    my $patch = File::Spec->catfile($dir, 'debian', 'patches', $patch_name);
     if (-s $patch_file) {
         copy($patch_file, $patch) ||
-            syserr(_g("failed to copy %s to %s"), $patch_file, $patch);
+            syserr(_g('failed to copy %s to %s'), $patch_file, $patch);
         chmod(0666 & ~ umask(), $patch) ||
                 syserr(_g("unable to change permission of `%s'"), $patch);
-        my $applied = File::Spec->catfile($dir, "debian", "patches", ".dpkg-source-applied");
+        my $applied = File::Spec->catfile($dir, 'debian', 'patches', '.dpkg-source-applied');
         open(my $applied_fh, '>>', $applied) ||
-            syserr(_g("cannot write %s"), $applied);
+            syserr(_g('cannot write %s'), $applied);
         print $applied_fh "$patch\n";
-        close($applied_fh) || syserr(_g("cannot close %s"), $applied);
+        close($applied_fh) || syserr(_g('cannot close %s'), $applied);
     } elsif (-e $patch) {
-        unlink($patch) || syserr(_g("cannot remove %s"), $patch);
+        unlink($patch) || syserr(_g('cannot remove %s'), $patch);
     }
     return $patch;
 }
@@ -608,9 +608,9 @@ sub _is_bad_patch_name {
     return 1 if not defined($patch_name);
     return 1 if not length($patch_name);
 
-    my $patch = File::Spec->catfile($dir, "debian", "patches", $patch_name);
+    my $patch = File::Spec->catfile($dir, 'debian', 'patches', $patch_name);
     if (-e $patch) {
-        warning(_g("cannot register changes in %s, this patch already exists"),
+        warning(_g('cannot register changes in %s, this patch already exists'),
                 $patch);
         return 1;
     }
@@ -639,28 +639,28 @@ sub do_commit {
 
     unless ($tmpdiff) {
         $tmpdiff = $self->generate_patch($dir, handle_binary => $handle_binary,
-                                         usage => "commit");
+                                         usage => 'commit');
         $binaryfiles->update_debian_source_include_binaries();
     }
     push @Dpkg::Exit::handlers, sub { unlink($tmpdiff) };
     unless (-s $tmpdiff) {
-        unlink($tmpdiff) || syserr(_g("cannot remove %s"), $tmpdiff);
-        info(_g("there are no local changes to record"));
+        unlink($tmpdiff) || syserr(_g('cannot remove %s'), $tmpdiff);
+        info(_g('there are no local changes to record'));
         return;
     }
     while (_is_bad_patch_name($dir, $patch_name)) {
         # Ask the patch name interactively
-        print STDOUT _g("Enter the desired patch name: ");
+        print STDOUT _g('Enter the desired patch name: ');
         chomp($patch_name = <STDIN>);
         $patch_name =~ s/\s+/-/g;
         $patch_name =~ s/\///g;
     }
-    mkpath(File::Spec->catdir($dir, "debian", "patches"));
+    mkpath(File::Spec->catdir($dir, 'debian', 'patches'));
     my $patch = $self->register_patch($dir, $tmpdiff, $patch_name);
-    system("sensible-editor", $patch);
-    unlink($tmpdiff) || syserr(_g("cannot remove %s"), $tmpdiff);
+    system('sensible-editor', $patch);
+    unlink($tmpdiff) || syserr(_g('cannot remove %s'), $tmpdiff);
     pop @Dpkg::Exit::handlers;
-    info(_g("local changes have been recorded in a new patch: %s"), $patch);
+    info(_g('local changes have been recorded in a new patch: %s'), $patch);
 }
 
 package Dpkg::Source::Package::V2::BinaryFiles;
@@ -679,7 +679,7 @@ sub new {
         allowed_binaries => {},
         seen_binaries => {},
         include_binaries_path =>
-            File::Spec->catfile($dir, "debian", "source", "include-binaries"),
+            File::Spec->catfile($dir, 'debian', 'source', 'include-binaries'),
     };
     bless $self, $class;
     $self->load_allowed_binaries();
@@ -696,8 +696,8 @@ sub load_allowed_binaries {
     my ($self) = @_;
     my $incbin_file = $self->{include_binaries_path};
     if (-f $incbin_file) {
-        open(my $incbin_fh, "<", $incbin_file) ||
-            syserr(_g("cannot read %s"), $incbin_file);
+        open(my $incbin_fh, '<', $incbin_file) ||
+            syserr(_g('cannot read %s'), $incbin_file);
         while (defined($_ = <$incbin_fh>)) {
             chomp; s/^\s*//; s/\s*$//;
             next if /^#/ or /^$/;
@@ -720,12 +720,12 @@ sub update_debian_source_include_binaries {
     return unless scalar(@unknown_binaries);
 
     my $incbin_file = $self->{include_binaries_path};
-    mkpath(File::Spec->catdir($self->{dir}, "debian", "source"));
-    open(my $incbin_fh, ">>", $incbin_file) ||
-        syserr(_g("cannot write %s"), $incbin_file);
+    mkpath(File::Spec->catdir($self->{dir}, 'debian', 'source'));
+    open(my $incbin_fh, '>>', $incbin_file) ||
+        syserr(_g('cannot write %s'), $incbin_file);
     foreach my $binary (@unknown_binaries) {
         print $incbin_fh "$binary\n";
-        info(_g("adding %s to %s"), $binary, "debian/source/include-binaries");
+        info(_g('adding %s to %s'), $binary, 'debian/source/include-binaries');
         $self->{allowed_binaries}{$binary} = 1;
     }
     close($incbin_fh);
diff --git a/scripts/Dpkg/Source/Package/V3/bzr.pm b/scripts/Dpkg/Source/Package/V3/bzr.pm
index 28c9935a8..9bc69f23e 100644
--- a/scripts/Dpkg/Source/Package/V3/bzr.pm
+++ b/scripts/Dpkg/Source/Package/V3/bzr.pm
@@ -24,7 +24,7 @@ package Dpkg::Source::Package::V3::bzr;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 use base 'Dpkg::Source::Package';
 
@@ -41,7 +41,7 @@ use Dpkg::Source::Archive;
 use Dpkg::Exit;
 use Dpkg::Source::Functions qw(erasedir);
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub import {
     foreach my $dir (split(/:/, $ENV{PATH})) {
@@ -49,28 +49,28 @@ sub import {
             return 1;
         }
     }
-    error(_g("cannot unpack bzr-format source package because " .
-             "bzr is not in the PATH"));
+    error(_g('cannot unpack bzr-format source package because ' .
+             'bzr is not in the PATH'));
 }
 
 sub sanity_check {
     my $srcdir = shift;
 
     if (! -d "$srcdir/.bzr") {
-        error(_g("source directory is not the top directory of a bzr repository (%s/.bzr not present), but Format bzr was specified"),
+        error(_g('source directory is not the top directory of a bzr repository (%s/.bzr not present), but Format bzr was specified'),
               $srcdir);
     }
 
     # Symlinks from .bzr to outside could cause unpack failures, or
     # point to files they shouldn't, so check for and don't allow.
     if (-l "$srcdir/.bzr") {
-        error(_g("%s is a symlink"), "$srcdir/.bzr");
+        error(_g('%s is a symlink'), "$srcdir/.bzr");
     }
     my $abs_srcdir = Cwd::abs_path($srcdir);
     find(sub {
         if (-l $_) {
             if (Cwd::abs_path(readlink($_)) !~ /^\Q$abs_srcdir\E(\/|$)/) {
-                error(_g("%s is a symlink to outside %s"),
+                error(_g('%s is a symlink to outside %s'),
                       $File::Find::name, $srcdir);
             }
         }
@@ -114,8 +114,8 @@ sub do_build {
     # Check for uncommitted files.
     # To support dpkg-source -i, remove any ignored files from the
     # output of bzr status.
-    open(my $bzr_status_fh, '-|', "bzr", "status") ||
-            subprocerr("bzr status");
+    open(my $bzr_status_fh, '-|', 'bzr', 'status') ||
+            subprocerr('bzr status');
     my @files;
     while (<$bzr_status_fh>) {
         chomp;
@@ -125,10 +125,10 @@ sub do_build {
             push @files, $_;
         }
     }
-    close($bzr_status_fh) || syserr(_g("bzr status exited nonzero"));
+    close($bzr_status_fh) || syserr(_g('bzr status exited nonzero'));
     if (@files) {
-        error(_g("uncommitted, not-ignored changes in working directory: %s"),
-              join(" ", @files));
+        error(_g('uncommitted, not-ignored changes in working directory: %s'),
+              join(' ', @files));
     }
 
     chdir($old_cwd) ||
@@ -138,11 +138,11 @@ sub do_build {
     push @Dpkg::Exit::handlers, sub { erasedir($tmp) };
     my $tardir = "$tmp/$dirname";
 
-    system("bzr", "branch", $dir, $tardir);
+    system('bzr', 'branch', $dir, $tardir);
     $? && subprocerr("bzr branch $dir $tardir");
 
     # Remove the working tree.
-    system("bzr", "remove-tree", $tardir);
+    system('bzr', 'remove-tree', $tardir);
 
     # Some branch metadata files are unhelpful.
     unlink("$tardir/.bzr/branch/branch-name",
@@ -150,7 +150,7 @@ sub do_build {
 
     # Create the tar file
     my $debianfile = "$basenamerev.bzr.tar." . $self->{options}{comp_ext};
-    info(_g("building %s in %s"),
+    info(_g('building %s in %s'),
          $sourcepackage, $debianfile);
     my $tar = Dpkg::Source::Archive->new(filename => $debianfile,
                                          compression => $self->{options}{compression},
@@ -177,18 +177,18 @@ sub do_extract {
 
     my @files = $self->get_files();
     if (@files > 1) {
-        error(_g("format v3.0 uses only one source file"));
+        error(_g('format v3.0 uses only one source file'));
     }
     my $tarfile = $files[0];
     if ($tarfile !~ /^\Q$basenamerev\E\.bzr\.tar\.$compression_re_file_ext$/) {
-        error(_g("expected %s, got %s"),
+        error(_g('expected %s, got %s'),
               "$basenamerev.bzr.tar.$compression_re_file_ext", $tarfile);
     }
 
     erasedir($newdirectory);
 
     # Extract main tarball
-    info(_g("unpacking %s"), $tarfile);
+    info(_g('unpacking %s'), $tarfile);
     my $tar = Dpkg::Source::Archive->new(filename => "$dscdir$tarfile");
     $tar->extract($newdirectory);
 
@@ -199,7 +199,7 @@ sub do_extract {
             syserr(_g("unable to chdir to `%s'"), $newdirectory);
 
     # Reconstitute the working tree.
-    system("bzr", "checkout");
+    system('bzr', 'checkout');
 
     chdir($old_cwd) ||
             syserr(_g("unable to chdir to `%s'"), $old_cwd);
diff --git a/scripts/Dpkg/Source/Package/V3/custom.pm b/scripts/Dpkg/Source/Package/V3/custom.pm
index 9ba8d5874..475a7cf46 100644
--- a/scripts/Dpkg/Source/Package/V3/custom.pm
+++ b/scripts/Dpkg/Source/Package/V3/custom.pm
@@ -18,7 +18,7 @@ package Dpkg::Source::Package::V3::custom;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 use base 'Dpkg::Source::Package';
 
@@ -26,7 +26,7 @@ use Dpkg;
 use Dpkg::Gettext;
 use Dpkg::ErrorHandling;
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub parse_cmdline_option {
     my ($self, $opt) = @_;
@@ -43,14 +43,14 @@ sub do_extract {
 sub can_build {
     my ($self, $dir) = @_;
     return (scalar(@{$self->{options}{ARGV}}),
-            _g("no files indicated on command line"));
+            _g('no files indicated on command line'));
 }
 
 sub do_build {
     my ($self, $dir) = @_;
     # Update real target format
     my $format = $self->{options}{target_format};
-    error(_g("--target-format option is missing")) unless $format;
+    error(_g('--target-format option is missing')) unless $format;
     $self->{fields}{'Format'} = $format;
     # Add all files
     foreach my $file (@{$self->{options}{ARGV}}) {
diff --git a/scripts/Dpkg/Source/Package/V3/git.pm b/scripts/Dpkg/Source/Package/V3/git.pm
index 863576f86..5bb83ed3c 100644
--- a/scripts/Dpkg/Source/Package/V3/git.pm
+++ b/scripts/Dpkg/Source/Package/V3/git.pm
@@ -22,7 +22,7 @@ package Dpkg::Source::Package::V3::git;
 use strict;
 use warnings;
 
-our $VERSION = "0.02";
+our $VERSION = '0.02';
 
 use base 'Dpkg::Source::Package';
 
@@ -36,7 +36,7 @@ use Dpkg::ErrorHandling;
 use Dpkg::Exit;
 use Dpkg::Source::Functions qw(erasedir);
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 # Remove variables from the environment that might cause git to do
 # something unexpected.
@@ -52,20 +52,20 @@ sub import {
             return 1;
         }
     }
-    error(_g("cannot unpack git-format source package because " .
-             "git is not in the PATH"));
+    error(_g('cannot unpack git-format source package because ' .
+             'git is not in the PATH'));
 }
 
 sub sanity_check {
     my $srcdir = shift;
 
     if (! -d "$srcdir/.git") {
-        error(_g("source directory is not the top directory of a git " .
-                 "repository (%s/.git not present), but Format git was " .
-                 "specified"), $srcdir);
+        error(_g('source directory is not the top directory of a git ' .
+                 'repository (%s/.git not present), but Format git was ' .
+                 'specified'), $srcdir);
     }
     if (-s "$srcdir/.gitmodules") {
-        error(_g("git repository %s uses submodules; this is not yet supported"),
+        error(_g('git repository %s uses submodules; this is not yet supported'),
               $srcdir);
     }
 
@@ -107,17 +107,17 @@ sub do_build {
     # To support dpkg-source -i, get a list of files
     # equivalent to the ones git status finds, and remove any
     # ignored files from it.
-    my @ignores = "--exclude-per-directory=.gitignore";
+    my @ignores = '--exclude-per-directory=.gitignore';
     my $core_excludesfile = `git config --get core.excludesfile`;
     chomp $core_excludesfile;
     if (length $core_excludesfile && -e $core_excludesfile) {
         push @ignores, "--exclude-from=$core_excludesfile";
     }
-    if (-e ".git/info/exclude") {
-        push @ignores, "--exclude-from=.git/info/exclude";
+    if (-e '.git/info/exclude') {
+        push @ignores, '--exclude-from=.git/info/exclude';
     }
-    open(my $git_ls_files_fh, '-|', "git", "ls-files", "--modified", "--deleted",
-         "-z", "--others", @ignores) || subprocerr("git ls-files");
+    open(my $git_ls_files_fh, '-|', 'git', 'ls-files', '--modified', '--deleted',
+         '-z', '--others', @ignores) || subprocerr('git ls-files');
     my @files;
     { local $/ = "\0";
       while (<$git_ls_files_fh>) {
@@ -128,10 +128,10 @@ sub do_build {
           }
       }
     }
-    close($git_ls_files_fh) || syserr(_g("git ls-files exited nonzero"));
+    close($git_ls_files_fh) || syserr(_g('git ls-files exited nonzero'));
     if (@files) {
-        error(_g("uncommitted, not-ignored changes in working directory: %s"),
-              join(" ", @files));
+        error(_g('uncommitted, not-ignored changes in working directory: %s'),
+              join(' ', @files));
     }
 
     # If a depth was specified, need to create a shallow clone and
@@ -146,29 +146,29 @@ sub do_build {
         my $clone_dir = "$tmp/repo.git";
         # file:// is needed to avoid local cloning, which does not
         # create a shallow clone.
-        info(_g("creating shallow clone with depth %s"),
+        info(_g('creating shallow clone with depth %s'),
                 $self->{options}{git_depth});
-        system("git", "clone", "--depth=" . $self->{options}{git_depth},
-                "--quiet", "--bare", "file://" . abs_path($dir), $clone_dir);
-        $? && subprocerr("git clone");
+        system('git', 'clone', '--depth=' . $self->{options}{git_depth},
+               '--quiet', '--bare', 'file://' . abs_path($dir), $clone_dir);
+        $? && subprocerr('git clone');
         chdir($clone_dir) ||
                 syserr(_g("unable to chdir to `%s'"), $clone_dir);
         $shallowfile = "$basenamerev.gitshallow";
-        system("cp", "-f", "shallow", "$old_cwd/$shallowfile");
-        $? && subprocerr("cp shallow");
+        system('cp', '-f', 'shallow', "$old_cwd/$shallowfile");
+        $? && subprocerr('cp shallow');
     }
 
     # Create the git bundle.
     my $bundlefile = "$basenamerev.git";
-    my @bundle_arg = $self->{options}{git_ref} ?
-        (@{$self->{options}{git_ref}}) : "--all";
-    info(_g("bundling: %s"), join(" ", @bundle_arg));
-    system("git", "bundle", "create", "$old_cwd/$bundlefile",
+    my @bundle_arg=$self->{options}{git_ref} ?
+        (@{$self->{options}{git_ref}}) : '--all';
+    info(_g('bundling: %s'), join(' ', @bundle_arg));
+    system('git', 'bundle', 'create', "$old_cwd/$bundlefile",
            @bundle_arg,
-           "HEAD", # ensure HEAD is included no matter what
-           "--", # avoids ambiguity error when referring to eg, a debian branch
+           'HEAD', # ensure HEAD is included no matter what
+           '--', # avoids ambiguity error when referring to eg, a debian branch
     );
-    $? && subprocerr("git bundle");
+    $? && subprocerr('git bundle');
 
     chdir($old_cwd) ||
         syserr(_g("unable to chdir to `%s'"), $old_cwd);
@@ -198,35 +198,35 @@ sub do_extract {
             if (! defined $bundle) {
                 $bundle = $file;
             } else {
-                error(_g("format v3.0 (git) uses only one .git file"));
+                error(_g('format v3.0 (git) uses only one .git file'));
             }
         } elsif ($file =~ /^\Q$basenamerev\E\.gitshallow$/) {
             if (! defined $shallow) {
                 $shallow = $file;
             } else {
-                error(_g("format v3.0 (git) uses only one .gitshallow file"));
+                error(_g('format v3.0 (git) uses only one .gitshallow file'));
             }
         } else {
-            error(_g("format v3.0 (git) unknown file: %s", $file));
+            error(_g('format v3.0 (git) unknown file: %s', $file));
         }
     }
     if (! defined $bundle) {
-        error(_g("format v3.0 (git) expected %s"), "$basenamerev.git");
+        error(_g('format v3.0 (git) expected %s'), "$basenamerev.git");
     }
 
     erasedir($newdirectory);
 
     # Extract git bundle.
-    info(_g("cloning %s"), $bundle);
-    system("git", "clone", "--quiet", $dscdir.$bundle, $newdirectory);
-    $? && subprocerr("git bundle");
+    info(_g('cloning %s'), $bundle);
+    system('git', 'clone', '--quiet', $dscdir . $bundle, $newdirectory);
+    $? && subprocerr('git bundle');
 
     if (defined $shallow) {
         # Move shallow info file into place, so git does not
         # try to follow parents of shallow refs.
-        info(_g("setting up shallow clone"));
-        system("cp", "-f",  $dscdir.$shallow, "$newdirectory/.git/shallow");
-        $? && subprocerr("cp");
+        info(_g('setting up shallow clone'));
+        system('cp', '-f',  $dscdir . $shallow, "$newdirectory/.git/shallow");
+        $? && subprocerr('cp');
     }
 
     sanity_check($newdirectory);
diff --git a/scripts/Dpkg/Source/Package/V3/native.pm b/scripts/Dpkg/Source/Package/V3/native.pm
index 726bc3905..de706f39a 100644
--- a/scripts/Dpkg/Source/Package/V3/native.pm
+++ b/scripts/Dpkg/Source/Package/V3/native.pm
@@ -18,7 +18,7 @@ package Dpkg::Source::Package::V3::native;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 use base 'Dpkg::Source::Package';
 
@@ -34,7 +34,7 @@ use Cwd;
 use File::Basename;
 use File::Temp qw(tempfile);
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub do_extract {
     my ($self, $newdirectory) = @_;
@@ -48,17 +48,17 @@ sub do_extract {
     my $tarfile;
     foreach my $file ($self->get_files()) {
 	if ($file =~ /^\Q$basenamerev\E\.tar\.$compression_re_file_ext$/) {
-            error(_g("multiple tarfiles in v1.0 source package")) if $tarfile;
+            error(_g('multiple tarfiles in v1.0 source package')) if $tarfile;
             $tarfile = $file;
 	} else {
-	    error(_g("unrecognized file for a native source package: %s"), $file);
+	    error(_g('unrecognized file for a native source package: %s'), $file);
 	}
     }
 
-    error(_g("no tarfile in Files field")) unless $tarfile;
+    error(_g('no tarfile in Files field')) unless $tarfile;
 
     erasedir($newdirectory);
-    info(_g("unpacking %s"), $tarfile);
+    info(_g('unpacking %s'), $tarfile);
     my $tar = Dpkg::Source::Archive->new(filename => "$dscdir$tarfile");
     $tar->extract($newdirectory);
 }
@@ -81,7 +81,7 @@ sub do_build {
     my $basenamerev = $self->get_basename(1);
     my $tarname = "$basenamerev.tar." . $self->{options}{comp_ext};
 
-    info(_g("building %s in %s"), $sourcepackage, $tarname);
+    info(_g('building %s in %s'), $sourcepackage, $tarname);
 
     my ($ntfh, $newtar) = tempfile("$tarname.new.XXXXXX",
                                    DIR => getcwd(), UNLINK => 0);
diff --git a/scripts/Dpkg/Source/Package/V3/quilt.pm b/scripts/Dpkg/Source/Package/V3/quilt.pm
index 7ebee244f..bca916b6b 100644
--- a/scripts/Dpkg/Source/Package/V3/quilt.pm
+++ b/scripts/Dpkg/Source/Package/V3/quilt.pm
@@ -18,7 +18,7 @@ package Dpkg::Source::Package::V3::quilt;
 use strict;
 use warnings;
 
-our $VERSION = "0.01";
+our $VERSION = '0.01';
 
 # Based on wig&pen implementation
 use base 'Dpkg::Source::Package::V2';
@@ -34,7 +34,7 @@ use Dpkg::Exit;
 use File::Spec;
 use File::Copy;
 
-our $CURRENT_MINOR_VERSION = "0";
+our $CURRENT_MINOR_VERSION = '0';
 
 sub init_options {
     my ($self) = @_;
@@ -75,15 +75,15 @@ sub can_build {
     my $quilt = $self->build_quilt_object($dir);
     $msg = $quilt->find_problems();
     return (0, $msg) if $msg;
-    return (1, "");
+    return (1, '');
 }
 
 sub get_autopatch_name {
     my ($self) = @_;
     if ($self->{options}{single_debian_patch}) {
-        return "debian-changes";
+        return 'debian-changes';
     } else {
-        return "debian-changes-" . $self->{fields}{'Version'};
+        return 'debian-changes-' . $self->{fields}{'Version'};
     }
 }
 
@@ -107,8 +107,8 @@ sub apply_patches {
     # Update debian/patches/series symlink if needed to allow quilt usage
     my $series = $quilt->get_series_file();
     my $basename = (File::Spec->splitpath($series))[2];
-    if ($basename ne "series") {
-        my $dest = $quilt->get_patch_file("series");
+    if ($basename ne 'series') {
+        my $dest = $quilt->get_patch_file('series');
         unlink($dest) if -l $dest;
         unless (-f _) { # Don't overwrite real files
             symlink($basename, $dest) ||
@@ -118,18 +118,18 @@ sub apply_patches {
 
     return unless scalar($quilt->series());
 
-    if ($opts{usage} eq "preparation" and
+    if ($opts{usage} eq 'preparation' and
         $self->{options}{unapply_patches} eq 'auto') {
         # We're applying the patches in --before-build, remember to unapply
         # them afterwards in --after-build
-        my $pc_unapply = $quilt->get_db_file(".dpkg-source-unapply");
-        open(my $unapply_fh, ">", $pc_unapply) ||
-            syserr(_g("cannot write %s"), $pc_unapply);
+        my $pc_unapply = $quilt->get_db_file('.dpkg-source-unapply');
+        open(my $unapply_fh, '>', $pc_unapply) ||
+            syserr(_g('cannot write %s'), $pc_unapply);
         close($unapply_fh);
     }
 
     # Apply patches
-    my $pc_applied = $quilt->get_db_file("applied-patches");
+    my $pc_applied = $quilt->get_db_file('applied-patches');
     $opts{timestamp} = fs_time($pc_applied);
     if ($opts{skip_auto}) {
         my $auto_patch = $self->get_autopatch_name();
@@ -146,7 +146,7 @@ sub unapply_patches {
 
     $opts{verbose} //= 1;
 
-    my $pc_applied = $quilt->get_db_file("applied-patches");
+    my $pc_applied = $quilt->get_db_file('applied-patches');
     my @applied = $quilt->applied();
     $opts{timestamp} = fs_time($pc_applied) if @applied;
 
@@ -180,9 +180,9 @@ sub do_build {
         if (scalar grep { $version eq $_ }
             @{$self->{options}{allow_version_of_quilt_db}})
         {
-            warning(_g("unsupported version of the quilt metadata: %s"), $version);
+            warning(_g('unsupported version of the quilt metadata: %s'), $version);
         } else {
-            error(_g("unsupported version of the quilt metadata: %s"), $version);
+            error(_g('unsupported version of the quilt metadata: %s'), $version);
         }
     }
 
@@ -192,9 +192,9 @@ sub do_build {
 sub after_build {
     my ($self, $dir) = @_;
     my $quilt = $self->build_quilt_object($dir);
-    my $pc_unapply = $quilt->get_db_file(".dpkg-source-unapply");
+    my $pc_unapply = $quilt->get_db_file('.dpkg-source-unapply');
     my $opt_unapply = $self->{options}{unapply_patches};
-    if (($opt_unapply eq "auto" and -e $pc_unapply) or $opt_unapply eq "yes") {
+    if (($opt_unapply eq 'auto' and -e $pc_unapply) or $opt_unapply eq 'yes') {
         unlink($pc_unapply);
         $self->unapply_patches($dir);
     }
@@ -207,7 +207,7 @@ sub check_patches_applied {
     my $next = $quilt->next();
     return if not defined $next;
 
-    my $first_patch = File::Spec->catfile($dir, "debian", "patches", $next);
+    my $first_patch = File::Spec->catfile($dir, 'debian', 'patches', $next);
     my $patch_obj = Dpkg::Source::Patch->new(filename => $first_patch);
     return unless $patch_obj->check_apply($dir);
 
@@ -217,7 +217,7 @@ sub check_patches_applied {
 sub _add_line {
     my ($file, $line) = @_;
 
-    open(my $file_fh, ">>", $file) || syserr(_g("cannot write %s"), $file);
+    open(my $file_fh, '>>', $file) || syserr(_g('cannot write %s'), $file);
     print $file_fh "$line\n";
     close($file_fh);
 }
@@ -225,10 +225,10 @@ sub _add_line {
 sub _drop_line {
     my ($file, $re) = @_;
 
-    open(my $file_fh, "<", $file) || syserr(_g("cannot read %s"), $file);
+    open(my $file_fh, '<', $file) || syserr(_g('cannot read %s'), $file);
     my @lines = <$file_fh>;
     close($file_fh);
-    open($file_fh, ">", $file) || syserr(_g("cannot write %s"), $file);
+    open($file_fh, '>', $file) || syserr(_g('cannot write %s'), $file);
     print($file_fh $_) foreach grep { not /^\Q$re\E\s*$/ } @lines;
     close($file_fh);
 }
@@ -241,16 +241,16 @@ sub register_patch {
     my @patches = $quilt->series();
     my $has_patch = (grep { $_ eq $patch_name } @patches) ? 1 : 0;
     my $series = $quilt->get_series_file();
-    my $applied = $quilt->get_db_file("applied-patches");
+    my $applied = $quilt->get_db_file('applied-patches');
     my $patch = $quilt->get_patch_file($patch_name);
 
     if (-s $tmpdiff) {
         copy($tmpdiff, $patch) ||
-            syserr(_g("failed to copy %s to %s"), $tmpdiff, $patch);
+            syserr(_g('failed to copy %s to %s'), $tmpdiff, $patch);
         chmod(0666 & ~ umask(), $patch) ||
             syserr(_g("unable to change permission of `%s'"), $patch);
     } elsif (-e $patch) {
-        unlink($patch) || syserr(_g("cannot remove %s"), $patch);
+        unlink($patch) || syserr(_g('cannot remove %s'), $patch);
     }
 
     if (-e $patch) {