[tools] testbot/PatchUtils: Only update the Wine files list for Wine patches.

[Francois Gouget]

Only update the list of Wine files if the patch is a Wine patch or will
trigger a make_makefiles run (which means any new file could be used).
Also reset IsWinePatch to evaluate later parts on their own merits.
But note that if we had MakeMakefiles=1 despite IsWinePatch=0 (previous
parts modified a Makefile.in file but are not unambiguously a Wine
patch), if the last part modifies one of the files newly added to the
Wine files list it will automatically get IsWinePatch=1; whereas if
presented as a single patch it would still have had MakeMakefiles=1 +
IsWinePatch=0. Fortunately the two cases are equivalent as far as
Patches::Submit() is concerned.

Signed-off-by: Francois Gouget 
---
For the following wtbsuite test:
WTBS S6.2 - Patch to a non-Wine file.

testbot/lib/WineTestBot/PatchUtils.pm | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/testbot/lib/WineTestBot/PatchUtils.pm b/testbot/lib/WineTestBot/PatchUtils.pm
index dda855d11..aeb874321 100644
--- a/testbot/lib/WineTestBot/PatchUtils.pm
+++ b/testbot/lib/WineTestBot/PatchUtils.pm
@@ -393,10 +393,14 @@ sub GetPatchImpacts($)

# Build a copy of the Wine files list reflecting the current situation.
       $Impacts->{WineFiles} = { %$_WineFiles } if (!$Impacts->{WineFiles});
-      map { $Impacts->{WineFiles}->{$_} = 1 } keys %{$Impacts->{NewFiles}};
-      map { delete $Impacts->{WineFiles}->{$_} } keys %{$Impacts->{DeletedFiles}};
-      $Impacts->{NewFiles} = {};
-      $Impacts->{DeletedFiles} = {};
+      if ($Impacts->{IsWinePatch} or $Impacts->{MakeMakefiles})
+      {
+        map { $Impacts->{WineFiles}->{$_} = 1 } keys %{$Impacts->{NewFiles}};
+        map { delete $Impacts->{WineFiles}->{$_} } keys %{$Impacts->{DeletedFiles}};
+        $Impacts->{NewFiles} = {};
+        $Impacts->{DeletedFiles} = {};
+        delete $Impacts->{IsWinePatch};
+      }

# The modules impacted by previous parts will still need to be built,
       # but only if the last part justifies a build. So make a backup.