centralize 'show' implementation of apt and apt-cache

The show commands have different styles in both binaries as the audience
is potentially very different, but that doesn't mean we need to separate
the implementation especially as they are slightly similar. This also
allows us to switch between the different show versions at runtime via
an option.

Git-Dch: Ignore

3 files changed, 174 insertions, 46 deletions

diff --git a/apt-private/private-cmndline.cc b/apt-private/private-cmndline.cc
index 81352d757..1299b85f0 100644
--- a/apt-private/private-cmndline.cc
+++ b/apt-private/private-cmndline.cc
@@ -319,6 +319,21 @@ std::vector<CommandLine::Args> getCommandArgs(char const * const Program, char c
 									/*}}}*/
 #undef CmdMatches
 #undef addArg
+static void BinarySpecificConfiguration(char const * const Binary)	/*{{{*/
+{
+   std::string const binary = flNotDir(Binary);
+   if (binary == "apt" || binary == "apt-config")
+   {
+      _config->CndSet("Binary::apt::APT::Cache::Show::Version", 2);
+      _config->CndSet("Binary::apt::APT::Cache::AllVersions", false);
+      _config->CndSet("Binary::apt::APT::Cache::ShowVirtuals", true);
+   }
+
+   _config->Set("Binary", binary);
+   std::string const conf = "Binary::" + binary;
+   _config->MoveSubTree(conf.c_str(), NULL);
+}
+									/*}}}*/
 void ParseCommandLine(CommandLine &CmdL, CommandLine::Dispatch * const Cmds, CommandLine::Args * const Args,/*{{{*/
       Configuration * const * const Cnf, pkgSystem ** const Sys, int const argc, const char *argv[], bool(*ShowHelp)(CommandLine &CmdL))
 {
@@ -330,12 +345,7 @@ void ParseCommandLine(CommandLine &CmdL, CommandLine::Dispatch * const Cmds, Com
    }
 
    if (likely(argc != 0 && argv[0] != NULL))
-   {
-      std::string const binary = flNotDir(argv[0]);
-      _config->Set("Binary", binary);
-      std::string const conf = "Binary::" + binary;
-      _config->MoveSubTree(conf.c_str(), NULL);
-   }
+      BinarySpecificConfiguration(argv[0]);
 
    if (CmdL.Parse(argc,argv) == false ||
        (Sys != NULL && pkgInitSystem(*_config, *Sys) == false))
diff --git a/apt-private/private-show.cc b/apt-private/private-show.cc
index 3a393b746..1bf712684 100644
--- a/apt-private/private-show.cc
+++ b/apt-private/private-show.cc
@@ -29,23 +29,15 @@
 #include <apti18n.h>
 									/*}}}*/
 
-namespace APT {
-   namespace Cmd {
-
-// DisplayRecord - Displays the complete record for the package		/*{{{*/
-// ---------------------------------------------------------------------
-static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
-                   std::ostream &out)
+static bool OpenPackagesFile(pkgCacheFile &CacheFile, pkgCache::VerIterator const &V,/*{{{*/
+      FileFd &PkgF, pkgCache::VerFileIterator &Vf)
 {
-   pkgCache *Cache = CacheFile.GetPkgCache();
+   pkgCache const * const Cache = CacheFile.GetPkgCache();
    if (unlikely(Cache == NULL))
       return false;
-   pkgDepCache *depCache = CacheFile.GetDepCache();
-   if (unlikely(depCache == NULL))
-      return false;
 
    // Find an appropriate file
-   pkgCache::VerFileIterator Vf = V.FileList();
+   Vf = V.FileList();
    for (; Vf.end() == false; ++Vf)
       if ((Vf.File()->Flags & pkgCache::Flag::NotSource) == 0)
 	 break;
@@ -57,6 +49,122 @@ static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
    if (I.IsOk() == false)
       return _error->Error(_("Package file %s is out of sync."),I.FileName());
 
+   // Read the record
+   return PkgF.Open(I.FileName(), FileFd::ReadOnly, FileFd::Extension);
+}
+									/*}}}*/
+static APT_PURE unsigned char const* skipDescriptionFields(unsigned char const * DescP)/*{{{*/
+{
+   char const * const TagName = "\nDescription";
+   size_t const TagLen = strlen(TagName);
+   while ((DescP = (unsigned char*)strchr((char*)DescP, '\n')) != NULL)
+   {
+      if (DescP[1] == ' ')
+	 DescP += 2;
+      else if (strncmp((char*)DescP, TagName, TagLen) == 0)
+	 DescP += TagLen;
+      else
+	 break;
+   }
+   if (DescP != NULL)
+      ++DescP;
+   return DescP;
+}
+									/*}}}*/
+bool DisplayRecordV1(pkgCacheFile &CacheFile, pkgCache::VerIterator const &V,/*{{{*/
+                   std::ostream &out)
+{
+   FileFd PkgF;
+   pkgCache::VerFileIterator Vf;
+   if (OpenPackagesFile(CacheFile, V, PkgF, Vf) == false)
+      return false;
+
+   pkgCache * const Cache = CacheFile.GetPkgCache();
+   if (unlikely(Cache == NULL))
+      return false;
+
+   // Read the record (and ensure that it ends with a newline and NUL)
+   unsigned char *Buffer = new unsigned char[Cache->HeaderP->MaxVerFileSize+2];
+   Buffer[Vf->Size] = '\n';
+   Buffer[Vf->Size+1] = '\0';
+   if (PkgF.Seek(Vf->Offset) == false ||
+       PkgF.Read(Buffer,Vf->Size) == false)
+   {
+      delete [] Buffer;
+      return false;
+   }
+
+   // Get a pointer to start of Description field
+   const unsigned char *DescP = (unsigned char*)strstr((char*)Buffer, "\nDescription");
+   if (DescP != NULL)
+      ++DescP;
+   else
+      DescP = Buffer + Vf->Size;
+
+   // Write all but Description
+   size_t const length = DescP - Buffer;
+   if (length != 0 && FileFd::Write(STDOUT_FILENO, Buffer, length) == false)
+   {
+      delete [] Buffer;
+      return false;
+   }
+
+   // Show the right description
+   pkgRecords Recs(*Cache);
+   pkgCache::DescIterator Desc = V.TranslatedDescription();
+   if (Desc.end() == false)
+   {
+      pkgRecords::Parser &P = Recs.Lookup(Desc.FileList());
+      out << "Description" << ( (strcmp(Desc.LanguageCode(),"") != 0) ? "-" : "" ) << Desc.LanguageCode() << ": " << P.LongDesc();
+      out << std::endl << "Description-md5: " << Desc.md5() << std::endl;
+
+      // Find the first field after the description (if there is any)
+      DescP = skipDescriptionFields(DescP);
+   }
+   // else we have no translation, so we found a lonely Description-md5 -> don't skip it
+
+   // write the rest of the buffer, but skip mixed in Descriptions* fields
+   while (DescP != NULL)
+   {
+      const unsigned char * const Start = DescP;
+      const unsigned char *End = (unsigned char*)strstr((char*)DescP, "\nDescription");
+      if (End == NULL)
+      {
+	 End = &Buffer[Vf->Size];
+	 DescP = NULL;
+      }
+      else
+      {
+	 ++End; // get the newline into the output
+	 DescP = skipDescriptionFields(End + strlen("Description"));
+      }
+      size_t const length = End - Start;
+      if (length != 0 && FileFd::Write(STDOUT_FILENO, Start, length) == false)
+      {
+	 delete [] Buffer;
+	 return false;
+      }
+   }
+   // write a final newline after the last field
+   out << std::endl;
+
+   delete [] Buffer;
+   return true;
+}
+									/*}}}*/
+static bool DisplayRecordV2(pkgCacheFile &CacheFile, pkgCache::VerIterator const &V,/*{{{*/
+                   std::ostream &out)
+{
+   FileFd PkgF;
+   pkgCache::VerFileIterator Vf;
+   if (OpenPackagesFile(CacheFile, V, PkgF, Vf) == false)
+      return false;
+
+   // Check and load the package list file
+   pkgCache::PkgFileIterator I = Vf.File();
+   if (I.IsOk() == false)
+      return _error->Error(_("Package file %s is out of sync."),I.FileName());
+
    // find matching sources.list metaindex
    pkgSourceList *SrcList = CacheFile.GetSourceList();
    pkgIndexFile *Index;
@@ -67,9 +175,6 @@ static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
    std::string source_index_file = Index->Describe(true);
 
    // Read the record
-   FileFd PkgF;
-   if (PkgF.Open(I.FileName(), FileFd::ReadOnly, FileFd::Extension) == false)
-      return false;
    pkgTagSection Tags;
    pkgTagFile TagF(&PkgF);
 
@@ -88,13 +193,15 @@ static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
    else
       package_size = _("unknown");
 
-   pkgDepCache::StateCache &state = (*depCache)[V.ParentPkg()];
-   bool is_installed = V.ParentPkg().CurrentVer() == V;
-   const char *manual_installed;
-   if (is_installed)
+   const char *manual_installed = nullptr;
+   if (V.ParentPkg().CurrentVer() == V)
+   {
+      pkgDepCache *depCache = CacheFile.GetDepCache();
+      if (unlikely(depCache == nullptr))
+	 return false;
+      pkgDepCache::StateCache &state = (*depCache)[V.ParentPkg()];
       manual_installed = !(state.Flags & pkgCache::Flag::Auto) ? "yes" : "no";
-   else
-      manual_installed = "";
+   }
 
    // FIXME: add verbose that does not do the removal of the tags?
    std::vector<pkgTagSection::Tag> RW;
@@ -115,7 +222,8 @@ static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
    RW.push_back(pkgTagSection::Tag::Remove("Size"));
    RW.push_back(pkgTagSection::Tag::Rewrite("Download-Size", package_size));
    // add
-   RW.push_back(pkgTagSection::Tag::Rewrite("APT-Manual-Installed", manual_installed));
+   if (manual_installed != nullptr)
+      RW.push_back(pkgTagSection::Tag::Rewrite("APT-Manual-Installed", manual_installed));
    RW.push_back(pkgTagSection::Tag::Rewrite("APT-Sources", source_index_file));
 
    FileFd stdoutfd;
@@ -124,6 +232,9 @@ static bool DisplayRecord(pkgCacheFile &CacheFile, pkgCache::VerIterator V,
       return _error->Error("Internal Error, Unable to parse a package record");
 
    // write the description
+   pkgCache * const Cache = CacheFile.GetPkgCache();
+   if (unlikely(Cache == NULL))
+      return false;
    pkgRecords Recs(*Cache);
    // FIXME: show (optionally) all available translations(?)
    pkgCache::DescIterator Desc = V.TranslatedDescription();
@@ -143,12 +254,19 @@ bool ShowPackage(CommandLine &CmdL)					/*{{{*/
 {
    pkgCacheFile CacheFile;
    CacheSetHelperVirtuals helper(true, GlobalError::NOTICE);
-   APT::CacheSetHelper::VerSelector const select = _config->FindB("APT::Cache::AllVersions", false) ?
+   APT::CacheSetHelper::VerSelector const select = _config->FindB("APT::Cache::AllVersions", true) ?
 			APT::CacheSetHelper::ALL : APT::CacheSetHelper::CANDIDATE;
    APT::VersionList const verset = APT::VersionList::FromCommandLine(CacheFile, CmdL.FileList + 1, select, helper);
+   int const ShowVersion = _config->FindI("APT::Cache::Show::Version", 1);
    for (APT::VersionList::const_iterator Ver = verset.begin(); Ver != verset.end(); ++Ver)
-      if (DisplayRecord(CacheFile, Ver, c1out) == false)
-	 return false;
+      if (ShowVersion <= 1)
+      {
+	 if (DisplayRecordV1(CacheFile, Ver, std::cout) == false)
+	    return false;
+      }
+      else
+	 if (DisplayRecordV2(CacheFile, Ver, c1out) == false)
+	    return false;
 
    if (select == APT::CacheSetHelper::CANDIDATE)
    {
@@ -158,14 +276,15 @@ bool ShowPackage(CommandLine &CmdL)					/*{{{*/
          _error->Notice(P_("There is %i additional record. Please use the '-a' switch to see it", "There are %i additional records. Please use the '-a' switch to see them.", records), records);
    }
 
-   for (APT::PackageSet::const_iterator Pkg = helper.virtualPkgs.begin();
-	Pkg != helper.virtualPkgs.end(); ++Pkg)
-   {
-       c1out << "Package: " << Pkg.FullName(true) << std::endl;
-       c1out << "State: " << _("not a real package (virtual)") << std::endl;
-       // FIXME: show providers, see private-cacheset.h
-       //        CacheSetHelperAPTGet::showVirtualPackageErrors()
-   }
+   if (_config->FindB("APT::Cache::ShowVirtuals", false) == true)
+      for (APT::PackageSet::const_iterator Pkg = helper.virtualPkgs.begin();
+	    Pkg != helper.virtualPkgs.end(); ++Pkg)
+      {
+	 c1out << "Package: " << Pkg.FullName(true) << std::endl;
+	 c1out << "State: " << _("not a real package (virtual)") << std::endl;
+	 // FIXME: show providers, see private-cacheset.h
+	 //        CacheSetHelperAPTGet::showVirtualPackageErrors()
+      }
 
    if (verset.empty() == true)
    {
@@ -178,5 +297,3 @@ bool ShowPackage(CommandLine &CmdL)					/*{{{*/
    return true;
 }
 									/*}}}*/
-} // namespace Cmd
-} // namespace APT
diff --git a/apt-private/private-show.h b/apt-private/private-show.h
index 359aeeb28..b38c65f2f 100644
--- a/apt-private/private-show.h
+++ b/apt-private/private-show.h
@@ -1,14 +1,15 @@
 #ifndef APT_PRIVATE_SHOW_H
 #define APT_PRIVATE_SHOW_H
 
+#include <apt-pkg/pkgcache.h>
 #include <apt-pkg/macros.h>
 
+#include <iostream>
+
 class CommandLine;
+class pkgCacheFile;
 
-namespace APT {
-   namespace Cmd {
+APT_PUBLIC bool ShowPackage(CommandLine &CmdL);
+APT_PUBLIC bool DisplayRecordV1(pkgCacheFile &CacheFile, pkgCache::VerIterator const &V, std::ostream &out);
 
-      APT_PUBLIC bool ShowPackage(CommandLine &CmdL);
-   }
-}
 #endif