gdi: fix incorrect usage of realloc.

Signed-off-by: Zhang Zhaolong <zhangzl2013@126.com>

diff --git a/libfreerdp/gdi/region.c b/libfreerdp/gdi/region.c
index 6584d43..ac72b68 100644 (file)
--- a/libfreerdp/gdi/region.c
+++ b/libfreerdp/gdi/region.c
@@ -384,8 +384,15 @@ INLINE int gdi_InvalidateRegion(HGDI_DC hdc, int x, int y, int w, int h)
 
        if ((hdc->hwnd->ninvalid + 1) > hdc->hwnd->count)
        {
-               hdc->hwnd->count *= 2;
-               cinvalid = (HGDI_RGN) realloc(cinvalid, sizeof(GDI_RGN) * (hdc->hwnd->count));
+               int new_cnt;
+               HGDI_RGN new_rgn;
+
+               new_cnt = hdc->hwnd->count * 2;
+               new_rgn = (HGDI_RGN) realloc(cinvalid, sizeof(GDI_RGN) * new_cnt);
+               if (!new_rgn)
+                       return -1;
+               hdc->hwnd->count = new_cnt;
+               cinvalid = new_rgn;
        }
 
        gdi_SetRgn(&cinvalid[hdc->hwnd->ninvalid++], x, y, w, h);