Only set opaque on initial alloc, add flag for clearing buffer on realloc.

svn path=/trunk/netsurf/; revision=13378

2 files changed, 5 insertions, 1 deletions

diff --git a/atari/bitmap.c b/atari/bitmap.c
index 9a0bd96ac..f991d9fc7 100755
--- a/atari/bitmap.c
+++ b/atari/bitmap.c
@@ -105,6 +105,7 @@ void * bitmap_realloc( int w, int h, short bpp, int rowstride, unsigned int stat
 		assert( 1 == 0 );
 		/* add some buffer for bad code */
 		bitmap->pixdata = malloc( newsize + 128 );
+		bitmap->opaque = false;
 	} else {
 		int oldsize = bitmap->rowstride * bitmap->height;
 		bool doalloc = ( state == BITMAP_GROW) ? (newsize > oldsize) : (newsize != oldsize);
@@ -116,10 +117,12 @@ void * bitmap_realloc( int w, int h, short bpp, int rowstride, unsigned int stat
 				return( NULL );
 		}
 	}
+	if( state & BITMAP_CLEAR ){
+		memset( bitmap->pixdata, 0x00, newsize + 128  );
+	}
 
 	bitmap->width = w;
 	bitmap->height = h;
-	bitmap->opaque = false;
 	bitmap->bpp = bpp;
 	bitmap->resized = NULL;
 	bitmap->rowstride = rowstride;
diff --git a/atari/bitmap.h b/atari/bitmap.h
index 783176053..d1756185d 100755
--- a/atari/bitmap.h
+++ b/atari/bitmap.h
@@ -22,6 +22,7 @@
 #define BITMAP_SHRINK	0
 #define BITMAP_GROW		0x1024
 #define BITMAP_MONOGLYPH 0x2048
+#define BITMAP_CLEAR	0x4096
 
 struct bitmap {
 	int width;