require explicit paths to dsc/control as we do for deb files

Otherwise a user is subject to unexpected content-injection depending on
which directory she happens to start apt in. This also cleans up the code
requiring less implementation details in build-dep which is always good.

Technically, this is an ABI break as we override virtual methods, but
that they weren't overridden was a mistake resulting in pure classes,
which shouldn't be pure, so they were unusable – and as they are new in
1.1 nobody is using them yet (and hopefully ever as they are borderline
implementation details).

Closes: 806693

1 files changed, 7 insertions, 1 deletions

diff --git a/apt-pkg/sourcelist.cc b/apt-pkg/sourcelist.cc
index 1e6b831be..6773b069f 100644
--- a/apt-pkg/sourcelist.cc
+++ b/apt-pkg/sourcelist.cc
@@ -544,11 +544,17 @@ void pkgSourceList::AddVolatileFile(pkgIndexFile * const File)		/*{{{*/
 									/*}}}*/
 bool pkgSourceList::AddVolatileFile(std::string const &File)		/*{{{*/
 {
+   // Note: FileExists matches directories and links, too!
    if (File.empty() || FileExists(File) == false)
       return false;
 
-   if (flExtension(File) == "deb")
+   std::string const ext = flExtension(File);
+   if (ext == "deb")
       AddVolatileFile(new debDebPkgFileIndex(File));
+   else if (ext == "dsc")
+      AddVolatileFile(new debDscFileIndex(File));
+   else if (FileExists(flCombine(File, "debian/control")))
+      AddVolatileFile(new debDscFileIndex(flCombine(File, "debian/control")));
    else
       return false;