[coverity] Protect GetEnhMetaFilePaletteEntries against bad handles

[Mike Hearn]

All the other emf functions check the handles here, so this one was
flagged up as missing. May as well complete the set.


Mike Hearn <mike at plan99.net>
Protect GetEnhMetaFilePaletteEntries against bad handles

diff --git a/dlls/gdi/enhmetafile.c b/dlls/gdi/enhmetafile.c
index 8725f9b..88a09bf 100644
--- a/dlls/gdi/enhmetafile.c
+++ b/dlls/gdi/enhmetafile.c
@@ -2571,6 +2571,12 @@ UINT WINAPI GetEnhMetaFilePaletteEntries
 
   TRACE( "(%p,%d,%p)\n", hEmf, cEntries, lpPe );
 
+  if (!enhHeader)
+  {
+    ERR("bad handle\n");
+    return 0;
+  }
+
   /* First check if there are any palettes associated with
      this metafile. */
   if ( enhHeader->nPalEntries == 0 ) return 0;