* src/base/ftbitmap.c (FT_Bitmap_Blend): Check target pitch.

Problem reported by Sender Ghost <lightside@gmx.com>.

ChangeLog

@@ -1,3 +1,9 @@
+2019-04-22  Werner Lemberg  <wl@gnu.org>
+
+	* src/base/ftbitmap.c (FT_Bitmap_Blend): Check target pitch.
+
+	Problem reported by Sender Ghost <lightside@gmx.com>.
+
 2019-04-22  Werner Lemberg  <wl@gnu.org>
 
 	Fix return value of `FT_Set_Named_Instance' (#56186).

src/base/ftbitmap.c

@@ -971,6 +971,13 @@
 
 
       pitch = target->pitch;
+      if ( !pitch )
+      {
+        FT_TRACE5(( "FT_Blend_Bitmap:"
+                    " zero target bitmap pitch is invalid\n" ));
+        return FT_THROW( Invalid_Argument );
+      }
+
       if ( pitch < 0 )
         pitch = -pitch;