shithub: jbig2

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ref: 1d120cab65c74fe97e4e4512f6a034f0fba0cac5
parent: b1bfe4ae823054ac2dc94af15246fa489304cf80
author: Robin Watts <[email protected]>
date: Tue Jan 24 08:20:11 EST 2012

Tweak jbig2dec to cope better with NULLs.

Fix various destructors in jbig2dec to cope with being called
with image = NULL. This cures a problem in mupdf where it SEGVs
when called on "1239 - skip invalid content streams.pdf" from the
sumatra test set.

--- a/jbig2_image.c
+++ b/jbig2_image.c
@@ -60,7 +60,8 @@
 /* clone an image pointer by bumping its reference count */
 Jbig2Image* jbig2_image_clone(Jbig2Ctx *ctx, Jbig2Image *image)
 {
-	image->refcount++;
+	if (image)
+		image->refcount++;
 	return image;
 }
 
@@ -67,6 +68,8 @@
 /* release an image pointer, freeing it it appropriate */
 void jbig2_image_release(Jbig2Ctx *ctx, Jbig2Image *image)
 {
+	if (image == NULL)
+		return;
 	image->refcount--;
 	if (!image->refcount) jbig2_image_free(ctx, image);
 }
@@ -74,7 +77,8 @@
 /* free a Jbig2Image structure and its associated memory */
 void jbig2_image_free(Jbig2Ctx *ctx, Jbig2Image *image)
 {
-	jbig2_free(ctx->allocator, image->data);
+	if (image)
+		jbig2_free(ctx->allocator, image->data);
 	jbig2_free(ctx->allocator, image);
 }