[Pixman] [PATCH] utils.c: Make image_endian_swap() deal with negative strides

[Søren Sandmann]

From: Søren Sandmann Pedersen <ssp at redhat.com>

Use a temporary variable s containing the absolute value of the stride
as the upper bound in the inner loops.
---
 test/utils.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/test/utils.c b/test/utils.c
index a83fc06..4f66fca 100644
--- a/test/utils.c
+++ b/test/utils.c
@@ -297,11 +297,12 @@ image_endian_swap (pixman_image_t *img)
     for (i = 0; i < height; i++)
     {
 	uint8_t *line_data = (uint8_t *)data + stride * i;
-	
+	int s = (stride >= 0)? stride : - stride;
+    	
 	switch (bpp)
 	{
 	case 1:
-	    for (j = 0; j < stride; j++)
+	    for (j = 0; j < s; j++)
 	    {
 		line_data[j] =
 		    ((line_data[j] & 0x80) >> 7) |
@@ -315,7 +316,7 @@ image_endian_swap (pixman_image_t *img)
 	    }
 	    break;
 	case 4:
-	    for (j = 0; j < stride; j++)
+	    for (j = 0; j < s; j++)
 	    {
 		line_data[j] = (line_data[j] >> 4) | (line_data[j] << 4);
 	    }
@@ -331,7 +332,7 @@ image_endian_swap (pixman_image_t *img)
 	    }
 	    break;
 	case 24:
-	    for (j = 0; j + 3 <= stride; j += 3)
+	    for (j = 0; j + 3 <= s; j += 3)
 	    {
 		char t1 = line_data[j + 0];
 		char t2 = line_data[j + 1];
@@ -343,7 +344,7 @@ image_endian_swap (pixman_image_t *img)
 	    }
 	    break;
 	case 32:
-	    for (j = 0; j + 4 <= stride; j += 4)
+	    for (j = 0; j + 4 <= s; j += 4)
 	    {
 		char t1 = line_data[j + 0];
 		char t2 = line_data[j + 1];
-- 
1.7.11.7