cabinet: Treat only -1 as an error from the FDICopy callback.

dlls/cabinet/fdi.c

@@ -2496,7 +2496,7 @@ BOOL __cdecl FDICopy(
   fdin.psz2 = (CAB(mii).nextinfo) ? CAB(mii).nextinfo : &emptystring;
   fdin.psz3 = pszCabPath;
 
-  if (((*pfnfdin)(fdintCABINET_INFO, &fdin))) {
+  if (pfnfdin(fdintCABINET_INFO, &fdin) == -1) {
     set_error( fdi, FDIERROR_USER_ABORT, 0 );
     goto bail_and_fail;
   }
@@ -2623,7 +2623,7 @@ BOOL __cdecl FDICopy(
       fdin.psz2 = (CAB(mii).prevname) ? CAB(mii).prevname : &emptystring;
       fdin.psz3 = (CAB(mii).previnfo) ? CAB(mii).previnfo : &emptystring;
 
-      if (((*pfnfdin)(fdintPARTIAL_FILE, &fdin))) {
+      if (pfnfdin(fdintPARTIAL_FILE, &fdin) == -1) {
         set_error( fdi, FDIERROR_USER_ABORT, 0 );
         goto bail_and_fail;
       }

dlls/cabinet/tests/fdi.c

@@ -744,7 +744,7 @@ static void test_FDIIsCabinet(void)
 
 static INT_PTR __cdecl CopyProgress(FDINOTIFICATIONTYPE fdint, PFDINOTIFICATION pfdin)
 {
-    return 0;
+    return 37;  /* doc says 0, but anything != -1 apparently means success as well */
 }
 
 static INT_PTR CDECL fdi_mem_open(char *name, int oflag, int pmode)