add --with-source option and Packages/Sources support

We support "./foobar.deb" as a way to install a deb file directly.
Recently .changes files were added. This highlights a problem as you
can't add the changes file without also trying to install all of them.
Now, it could also be handy to add entire Packages/Sources files to
perhaps get a bunch of packages in without installing them all
implicitly.

This commit introduces --with-source which allows to add *.deb, *.changes,
*.dsc, source-dirs, Packages & Sources files (the later can also be
compressed) without also installing them.

3 files changed, 45 insertions, 3 deletions

diff --git a/apt-pkg/deb/debindexfile.cc b/apt-pkg/deb/debindexfile.cc
index 6a23b2c00..65bd3e6ee 100644
--- a/apt-pkg/deb/debindexfile.cc
+++ b/apt-pkg/deb/debindexfile.cc
@@ -80,7 +80,11 @@ debPackagesIndex::debPackagesIndex(IndexTarget const &Target, bool const Trusted
 std::string debPackagesIndex::ArchiveInfo(pkgCache::VerIterator const &Ver) const
 {
    std::string Res = Target.Description;
-   Res.erase(Target.Description.rfind(' '));
+   {
+      auto const space = Target.Description.rfind(' ');
+      if (space != std::string::npos)
+	 Res.erase(space);
+   }
 
    Res += " ";
    Res += Ver.ParentPkg().Name();
diff --git a/apt-pkg/indexfile.cc b/apt-pkg/indexfile.cc
index b1435d32c..934943205 100644
--- a/apt-pkg/indexfile.cc
+++ b/apt-pkg/indexfile.cc
@@ -151,7 +151,13 @@ std::string IndexTarget::Option(OptionKeys const EnumKey) const		/*{{{*/
       APT_CASE(ALLOW_WEAK);
       APT_CASE(ALLOW_DOWNGRADE_TO_INSECURE);
 #undef APT_CASE
-      case FILENAME: return _config->FindDir("Dir::State::lists") + URItoFileName(URI);
+      case FILENAME:
+      {
+	 auto const M = Options.find("FILENAME");
+	 if (M == Options.end())
+	    return _config->FindDir("Dir::State::lists") + URItoFileName(URI);
+	 return M->second;
+      }
       case EXISTING_FILENAME:
 	 std::string const filename = Option(FILENAME);
 	 std::vector<std::string> const types = VectorizeString(Option(COMPRESSIONTYPES), ' ');
diff --git a/apt-pkg/sourcelist.cc b/apt-pkg/sourcelist.cc
index 000539582..f4a84cc9b 100644
--- a/apt-pkg/sourcelist.cc
+++ b/apt-pkg/sourcelist.cc
@@ -328,6 +328,9 @@ bool pkgSourceList::ReadMainList()
       // Only warn if there is no sources.list file.
       _error->WarningE("RealFileExists", _("Unable to read %s"), Main.c_str());
 
+   for (auto && file: _config->FindVector("APT::Sources::With"))
+      Res &= AddVolatileFile(file, nullptr);
+
    return Res;
 }
 									/*}}}*/
@@ -544,6 +547,22 @@ void pkgSourceList::AddVolatileFile(pkgIndexFile * const File)		/*{{{*/
       VolatileFiles.push_back(File);
 }
 									/*}}}*/
+static bool fileNameMatches(std::string const &filename, std::string const &idxtype)/*{{{*/
+{
+   for (auto && type: APT::Configuration::getCompressionTypes())
+   {
+      if (type == "uncompressed")
+      {
+	 if (filename == idxtype || APT::String::Endswith(filename, '_' + idxtype))
+	    return true;
+      }
+      else if (filename == idxtype + '.' + type ||
+	    APT::String::Endswith(filename, '_' + idxtype + '.' + type))
+	 return true;
+   }
+   return false;
+}
+									/*}}}*/
 bool pkgSourceList::AddVolatileFile(std::string const &File, std::vector<std::string> * const VolatileCmdL)/*{{{*/
 {
    // Note: FileExists matches directories and links, too!
@@ -574,7 +593,20 @@ bool pkgSourceList::AddVolatileFile(std::string const &File, std::vector<std::st
       return true;
    }
    else
-      return false;
+   {
+      auto const filename = flNotDir(File);
+      auto const Target = IndexTarget(File, filename, File, "file:" + File, false, true, {
+	 { "FILENAME", File },
+	 { "REPO_URI", "file:" + flAbsPath(flNotFile(File)) + '/' },
+	 { "COMPONENT", "volatile-packages-file" },
+      });
+      if (fileNameMatches(filename, "Packages"))
+	 AddVolatileFile(new debPackagesIndex(Target, true));
+      else if (fileNameMatches(filename, "Sources"))
+	 AddVolatileFile(new debSourcesIndex(Target, true));
+      else
+	 return false;
+   }
 
    if (VolatileCmdL != nullptr)
       VolatileCmdL->push_back(File);