[Driver] Fix recognizing newer OpenSUSE versions

[mgorny]

Summary

Fix recognizing newer OpenSUSE versions that combine the two version
components into 'VERSION = x.y'. The check was written against an older
version that kept those two split as VERSION and PATCHLEVEL.

[bruno]

Can you add a testcase?

[mgorny]

In D26850#599983, @bruno wrote:

Can you add a testcase?

The test case is included in D25869 — that's how I noticed it being broken ;-). My original intent was to commit the refactor, then this fix, then the test case. I can move the failing test case here if you insist but I think that's just an unnecessary work.

[mgorny]

Ping. @bruno, did you see my reply?

[bruno]

Ok, seems reasonable. If there are any additional fixes you find out before committing the other one, please include the test in the patch instead. Thanks!

LGTM

cfe/trunk/lib/Driver/Distro.cpp

static Distro::DistroType DetectDistro(vfs::FileSystem &VFS) {
   if (File) {
     StringRef Data = File.get()->getBuffer();
     SmallVector<StringRef, 8> Lines;
     Data.split(Lines, "\n");
     for (const StringRef& Line : Lines) {
       if (!Line.trim().startswith("VERSION"))
         continue;
       std::pair<StringRef, StringRef> SplitLine = Line.split('=');
+      // Old versions have split VERSION and PATCHLEVEL
+      // Newer versions use VERSION = x.y
+      std::pair<StringRef, StringRef> SplitVer = SplitLine.second.trim().split('.');
       int Version;
+
       // OpenSUSE/SLES 10 and older are not supported and not compatible
       // with our rules, so just treat them as Distro::UnknownDistro.
-      if (!SplitLine.second.trim().getAsInteger(10, Version) &&
-          Version > 10)
+      if (!SplitVer.first.getAsInteger(10, Version) && Version > 10)
         return Distro::OpenSUSE;
       return Distro::UnknownDistro;
     }
     return Distro::UnknownDistro;
   }
 
   if (VFS.exists("/etc/exherbo-release"))
     return Distro::Exherbo;
 
   if (VFS.exists("/etc/arch-release"))
     return Distro::ArchLinux;
 
   return Distro::UnknownDistro;
 }
 
 Distro::Distro(vfs::FileSystem &VFS) : DistroVal(DetectDistro(VFS)) {}