[PATCH 1/2] shell32/iconcache: Prevent the imagelists from going out of sync when loading an icon

[Gabriel Ivăncescu]

When populating the imagelists cache with icons of different sizes, it
can happen that only some icon sizes actually succeed the extraction,
with others failing with a NULL handle. This is especially true with some
broken "executable packers" where for example, a 32x32 icon loads okay,
but a 16x16 fails. Even when PrivateExtractIconsW succeeds, the returned
handle can still be NULL, leading to the ImageLists becoming out of sync.

This fixes a regression, because at some point, we stopped failing if one
icon failed to extract, so when SIC_IconAppend called ImageList_AddIcon
with a NULL icon handle, it would go out of sync.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45696
Signed-off-by: Gabriel Ivăncescu <gabrielopcode at gmail.com>
---
 dlls/shell32/iconcache.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/dlls/shell32/iconcache.c b/dlls/shell32/iconcache.c
index 6107e0c..44422ab 100644
--- a/dlls/shell32/iconcache.c
+++ b/dlls/shell32/iconcache.c
@@ -364,13 +364,14 @@ static INT SIC_LoadIcon (const WCHAR *sourcefile, INT index, DWORD flags)
     HICON hshortcuts[ARRAY_SIZE(hicons)] = { 0 };
     unsigned int i;
     SIZE size;
-    int ret;
+    INT ret = -1;
 
     for (i = 0; i < ARRAY_SIZE(hicons); i++)
     {
         get_imagelist_icon_size( i, &size );
         if (!PrivateExtractIconsW( sourcefile, index, size.cx, size.cy, &hicons[i], 0, 1, 0 ))
             WARN("Failed to load icon %d from %s.\n", index, debugstr_w(sourcefile));
+        if (!hicons[i]) goto fail;
     }
 
     if (flags & GIL_FORSHORTCUT)
@@ -403,6 +404,8 @@ static INT SIC_LoadIcon (const WCHAR *sourcefile, INT index, DWORD flags)
     }
 
     ret = SIC_IconAppend( sourcefile, index, hicons, flags );
+
+fail:
     for (i = 0; i < ARRAY_SIZE(hicons); i++)
         DestroyIcon(hicons[i]);
     return ret;
-- 
2.19.1