fix M-A:foreign provides creation for unknown archs

Architectures for packages which do not belong to the native nor a
foreign architecture (dubbed barbarian for now) which are marked
M-A:foreign still provide in their own architecture even if not for
others. Also, other M-A:foreign (and allowed) packages provide in these
barbarian architectures.

apt-pkg/deb/deblistparser.cc

@@ -907,8 +907,12 @@ bool debListParser::ParseProvides(pkgCache::VerIterator &Ver)
 	       return false;
 	 } else if ((Ver->MultiArch & pkgCache::Version::Foreign) == pkgCache::Version::Foreign) {
 	    if (APT::Configuration::checkArchitecture(Arch))
+	    {
 	       if (NewProvidesAllArch(Ver, Package, Version, 0) == false)
 		  return false;
+	    }
+	    else if (NewProvides(Ver, Package, Arch, Version, 0) == false)
+	       return false;
 	 } else {
 	    if ((Ver->MultiArch & pkgCache::Version::Allowed) == pkgCache::Version::Allowed)
 	    {

apt-pkg/pkgcachegen.cc

@@ -572,8 +572,7 @@ bool pkgCacheGenerator::NewPackage(pkgCache::PkgIterator &Pkg, StringView Name,
    }
    else // Group the Packages together
    {
-      // but first get implicit provides done
-      if (APT::Configuration::checkArchitecture(Pkg.Arch()) == true)
+      // if sibling is provided by another package, this one is too
       {
 	 pkgCache::PkgIterator const M = Grp.FindPreferredPkg(false); // native or any foreign pkg will do
 	 if (M.end() == false) {
@@ -588,22 +587,31 @@ bool pkgCacheGenerator::NewPackage(pkgCache::PkgIterator &Pkg, StringView Name,
 	       if ((Ver->MultiArch & pkgCache::Version::Allowed) == pkgCache::Version::Allowed ||
 	           ((Ver->MultiArch & pkgCache::Version::Foreign) == pkgCache::Version::Foreign &&
 			(Prv->Flags & pkgCache::Flag::MultiArchImplicit) == 0))
+	       {
+		  if (APT::Configuration::checkArchitecture(Ver.ParentPkg().Arch()) == false)
+		     continue;
 		  if (NewProvides(Ver, Pkg, Prv->ProvideVersion, Prv->Flags) == false)
 		     return false;
+	       }
 	    }
 	 }
-
-
+      }
+      // let M-A:foreign package siblings provide this package
+      {
 	 pkgCache::PkgIterator P;
 	 pkgCache::VerIterator Ver;
 	 Dynamic<pkgCache::PkgIterator> DynP(P);
 	 Dynamic<pkgCache::VerIterator> DynVer(Ver);
 
 	 for (P = Grp.PackageList(); P.end() == false;  P = Grp.NextPkg(P))
+	 {
+	    if (APT::Configuration::checkArchitecture(P.Arch()) == false)
+	       continue;
 	    for (Ver = P.VersionList(); Ver.end() == false; ++Ver)
 	       if ((Ver->MultiArch & pkgCache::Version::Foreign) == pkgCache::Version::Foreign)
 		  if (NewProvides(Ver, Pkg, Ver->VerStr, pkgCache::Flag::MultiArchImplicit) == false)
 		     return false;
+	 }
       }
       // and negative dependencies, don't forget negative dependencies
       {

test/integration/test-multiarch-allowed

@@ -255,7 +255,9 @@ configarchitecture 'amd64' 'i386'
 insertinstalledpackage 'foo' 'armel' '1' 'Multi-Arch: allowed'
 insertinstalledpackage 'coolfoo' 'armel' '1' 'Multi-Arch:allowed
 Provides: coolbar'
+insertinstalledpackage 'bar-needer' 'armel' '1.0' 'Depends: coolbar:any'
 
+testsuccess aptget check
 testsuccessequal 'Reading package lists...
 Building dependency tree...
 The following additional packages will be installed:
@@ -293,7 +295,7 @@ The following packages will be REMOVED:
 The following NEW packages will be installed:
   coolfoo needscoolfoover0
 0 upgraded, 2 newly installed, 1 to remove and 0 not upgraded.
-Remv coolfoo:armel [1]
+Remv coolfoo:armel [1] [bar-needer:armel ]
 Inst coolfoo (1 unstable [amd64])
 Inst needscoolfoover0 (1 unstable [amd64])
 Conf coolfoo (1 unstable [amd64])

test/integration/test-multiarch-foreign

@@ -250,7 +250,9 @@ msgmsg 'switch to multi-arch with barbarian architecture'
 insertinstalledpackage 'foo' 'armhf' '1.0' 'Multi-Arch: foreign'
 insertinstalledpackage 'bar' 'armhf' '1.0' 'Provides: bar-provider
 Multi-Arch: foreign'
+insertinstalledpackage 'bar-needer' 'armhf' '1.0' 'Depends: bar-provider'
 
+testsuccess aptget check
 testsuccessequal 'Reading package lists...
 Building dependency tree...
 The following additional packages will be installed:
@@ -274,8 +276,12 @@ The following packages will be REMOVED:
 The following NEW packages will be installed:
   bar cool-bar
 0 upgraded, 2 newly installed, 1 to remove and 0 not upgraded.
-Remv bar:armhf [1.0]
+Remv bar:armhf [1.0] [bar-needer:armhf ]
 Inst bar (1.0 unstable [amd64])
 Inst cool-bar (1.0 unstable [amd64])
 Conf bar (1.0 unstable [amd64])
 Conf cool-bar (1.0 unstable [amd64])' aptget install cool-bar -s
+
+# a barbarian doesn't satisfy another either
+insertinstalledpackage 'bar-needer2' 's390x' '1.0' 'Depends: bar-provider'
+testfailure aptget check