[PATCH] ole32: handle length=0 in save datacache

[Marcus Meissner]

The ole2 test crashes for me, reason is that length is 0
and we use length-1 for accessing whats returned.

Signed-off-by: Marcus Meissner <marcus at jet.franken.de>
---
 dlls/ole32/datacache.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dlls/ole32/datacache.c b/dlls/ole32/datacache.c
index 2907426f62..d08d2db6e2 100644
--- a/dlls/ole32/datacache.c
+++ b/dlls/ole32/datacache.c
@@ -480,7 +480,12 @@ static HRESULT read_clipformat(IStream *stream, CLIPFORMAT *clipformat)
     }
     else
     {
-        char *format_name = HeapAlloc(GetProcessHeap(), 0, length);
+        char *format_name;
+
+        if (!length)
+            return DV_E_CLIPFORMAT;
+
+        format_name = HeapAlloc(GetProcessHeap(), 0, length);
         if (!format_name)
             return E_OUTOFMEMORY;
         hr = IStream_Read(stream, format_name, length, &read);
-- 
2.14.3