Extend apt build-dep pkg/release to switch dep as needed

apt install pkg/release follows versioned dependencies in the candidate
switching if the current candidate does not satisfy the dependency,
so for uniformity the same should be supported in build-dep.

2 files changed, 42 insertions, 8 deletions

diff --git a/apt-private/private-install.cc b/apt-private/private-install.cc
index e1beb21c6..c9e45cc00 100644
--- a/apt-private/private-install.cc
+++ b/apt-private/private-install.cc
@@ -945,13 +945,21 @@ bool TryToInstall::propergateReleaseCandiateSwitching(std::list<std::pair<pkgCac
 	 c != Changed.end(); ++c)
    {
       if (c->second.end() == true)
+      {
+	 auto const pkgname = c->first.ParentPkg().FullName(true);
+	 if (APT::String::Startswith(pkgname, "builddeps:"))
+	    continue;
 	 ioprintf(out, _("Selected version '%s' (%s) for '%s'\n"),
-	       c->first.VerStr(), c->first.RelStr().c_str(), c->first.ParentPkg().FullName(true).c_str());
+	       c->first.VerStr(), c->first.RelStr().c_str(), pkgname.c_str());
+      }
       else if (c->first.ParentPkg()->Group != c->second.ParentPkg()->Group)
       {
+	 auto pkgname = c->second.ParentPkg().FullName(true);
+	 if (APT::String::Startswith(pkgname, "builddeps:"))
+	    pkgname.replace(0, strlen("builddeps"), "src");
 	 pkgCache::VerIterator V = (*Cache)[c->first.ParentPkg()].CandidateVerIter(*Cache);
 	 ioprintf(out, _("Selected version '%s' (%s) for '%s' because of '%s'\n"), V.VerStr(),
-	       V.RelStr().c_str(), V.ParentPkg().FullName(true).c_str(), c->second.ParentPkg().FullName(true).c_str());
+	       V.RelStr().c_str(), V.ParentPkg().FullName(true).c_str(), pkgname.c_str());
       }
    }
    return Success;
diff --git a/apt-private/private-source.cc b/apt-private/private-source.cc
index 32651cfdb..a24493421 100644
--- a/apt-private/private-source.cc
+++ b/apt-private/private-source.cc
@@ -658,7 +658,15 @@ bool DoBuildDep(CommandLine &CmdL)
       StripMultiArch = true;
 
    std::ostringstream buildDepsPkgFile;
-   std::vector<std::pair<std::string,std::string>> pseudoPkgs;
+   struct PseudoPkg
+   {
+      std::string name;
+      std::string arch;
+      std::string release;
+      PseudoPkg(std::string const &n, std::string const &a, std::string const &r) :
+	 name(n), arch(a), release(r) {}
+   };
+   std::vector<PseudoPkg> pseudoPkgs;
    // deal with the build essentials first
    {
       std::vector<pkgSrcRecords::Parser::BuildDepRec> BuildDeps;
@@ -675,7 +683,7 @@ bool DoBuildDep(CommandLine &CmdL)
       std::string const pseudo = "builddeps:essentials";
       std::string const nativeArch = _config->Find("APT::Architecture");
       WriteBuildDependencyPackage(buildDepsPkgFile, pseudo, nativeArch, BuildDeps);
-      pseudoPkgs.emplace_back(pseudo, nativeArch);
+      pseudoPkgs.emplace_back(pseudo, nativeArch, "");
    }
 
    // Read the source list
@@ -703,7 +711,7 @@ bool DoBuildDep(CommandLine &CmdL)
 	    std::string const pseudo = std::string("builddeps:") + Src;
 	    WriteBuildDependencyPackage(buildDepsPkgFile, pseudo, pseudoArch,
 		  GetBuildDeps(Last.get(), Src.c_str(), StripMultiArch, hostArch));
-	    pseudoPkgs.emplace_back(pseudo, pseudoArch);
+	    pseudoPkgs.emplace_back(pseudo, pseudoArch, "");
 	 }
       }
       else
@@ -731,7 +739,13 @@ bool DoBuildDep(CommandLine &CmdL)
 	 std::string const pseudo = std::string("builddeps:") + Src;
 	 WriteBuildDependencyPackage(buildDepsPkgFile, pseudo, pseudoArch,
 	       GetBuildDeps(Last, Src.c_str(), StripMultiArch, hostArch));
-	 pseudoPkgs.emplace_back(pseudo, pseudoArch);
+	 std::string reltag = *I;
+	 size_t found = reltag.find_last_of("/");
+	 if (found == std::string::npos)
+	    reltag.clear();
+	 else
+	    reltag.erase(0, found + 1);
+	 pseudoPkgs.emplace_back(pseudo, pseudoArch, std::move(reltag));
       }
    }
 
@@ -745,12 +759,24 @@ bool DoBuildDep(CommandLine &CmdL)
    {
       pkgDepCache::ActionGroup group(Cache);
       TryToInstall InstallAction(Cache, &Fix, false);
+      std::list<std::pair<pkgCache::VerIterator, std::string>> candSwitch;
+      for (auto const &pkg: pseudoPkgs)
+      {
+	 pkgCache::PkgIterator const Pkg = Cache->FindPkg(pkg.name, pkg.arch);
+	 if (Pkg.end())
+	    continue;
+	 if (pkg.release.empty())
+	    Cache->SetCandidateVersion(Pkg.VersionList());
+	 else
+	    candSwitch.emplace_back(Pkg.VersionList(), pkg.release);
+      }
+      if (candSwitch.empty() == false)
+	 InstallAction.propergateReleaseCandiateSwitching(candSwitch, c0out);
       for (auto const &pkg: pseudoPkgs)
       {
-	 pkgCache::PkgIterator const Pkg = Cache->FindPkg(pkg.first, pkg.second);
+	 pkgCache::PkgIterator const Pkg = Cache->FindPkg(pkg.name, pkg.arch);
 	 if (Pkg.end())
 	    continue;
-	 Cache->SetCandidateVersion(Pkg.VersionList());
 	 InstallAction(Cache[Pkg].CandidateVerIter(Cache));
 	 removeAgain.push_back(Pkg);
       }