* image.c: Improve checking for integer overflow.

(check_image_size): Assume that f is nonnull, since
it is always nonnull in practice.  This is one less thing to
worry about when checking for integer overflow later.
(x_check_image_size): New function, which checks for integer
overflow issues inside X.
(x_create_x_image_and_pixmap, xbm_read_bitmap_data): Use it.
This removes the need for a memory_full check.
(xbm_image_p): Rewrite to avoid integer multiplication overflow.
(Create_Pixmap_From_Bitmap_Data, xbm_load): Use x_check_image_size.
(xbm_read_bitmap_data): Change locals back to 'int', since
their values must fit in 'int'.
(xpm_load_image, png_load, tiff_load):
Invoke x_create_x_image_and_pixmap earlier,
to avoid much needless work if the image is too large.
(tiff_load): Treat overly large images as if
x_create_x_image_and_pixmap failed, not as malloc failures.
(gs_load): Use x_check_image_size.

1 files changed, 21 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c986030fcf8..e07b906b56d 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,24 @@
+2011-07-14  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * image.c: Improve checking for integer overflow.
+        (check_image_size): Assume that f is nonnull, since
+        it is always nonnull in practice.  This is one less thing to
+        worry about when checking for integer overflow later.
+        (x_check_image_size): New function, which checks for integer
+        overflow issues inside X.
+        (x_create_x_image_and_pixmap, xbm_read_bitmap_data): Use it.
+        This removes the need for a memory_full check.
+        (xbm_image_p): Rewrite to avoid integer multiplication overflow.
+        (Create_Pixmap_From_Bitmap_Data, xbm_load): Use x_check_image_size.
+        (xbm_read_bitmap_data): Change locals back to 'int', since
+        their values must fit in 'int'.
+        (xpm_load_image, png_load, tiff_load):
+        Invoke x_create_x_image_and_pixmap earlier,
+        to avoid much needless work if the image is too large.
+        (tiff_load): Treat overly large images as if
+        x_create_x_image_and_pixmap failed, not as malloc failures.
+        (gs_load): Use x_check_image_size.
+
 2011-07-13  Paul Eggert  <eggert@cs.ucla.edu>
 
         * gtkutil.c: Omit integer casts.