From 9dc9f24884e1b580448f12ccd50909b6aee3cb53 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sun, 14 Aug 2011 11:33:27 +0100
Subject: [PATCH] script: leave the tail of the RGB24 data unmolested

We clear past the end of the row so that we don't trigger valgrind
warning leaving harmless uninitialised bits inside the input image.
However, for RGB24 the input rowlen is 3*width, whereas we write 4*width
of data, so we need to take account of that and ensure we clear beyond
the end of the written data, not the read data.

Fixes reading of RGB24 input.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 util/cairo-script/cairo-script-operators.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/util/cairo-script/cairo-script-operators.c b/util/cairo-script/cairo-script-operators.c
index 5904f5a16..9576f208a 100644
--- a/util/cairo-script/cairo-script-operators.c
+++ b/util/cairo-script/cairo-script-operators.c
@@ -2849,7 +2849,7 @@ _image_read_raw (csi_file_t *src,
 {
     cairo_surface_t *image;
     uint8_t *bp, *data;
-    int rem, len, ret, x, rowlen, stride;
+    int rem, len, ret, x, rowlen, instride, stride;
     cairo_status_t status;
 
     stride = cairo_format_stride_for_width (format, width);
@@ -2870,22 +2870,23 @@ _image_read_raw (csi_file_t *src,
 
     switch (format) {
     case CAIRO_FORMAT_A1:
-	rowlen = (width+7)/8;
+	instride = rowlen = (width+7)/8;
 	break;
     case CAIRO_FORMAT_A8:
-	rowlen = width;
+	instride = rowlen = width;
 	break;
     case CAIRO_FORMAT_RGB16_565:
-	rowlen = 2 * width;
+	instride = rowlen = 2 * width;
 	break;
     case CAIRO_FORMAT_RGB24:
 	rowlen = 3 * width;
+	instride = 4 *width;
 	break;
     default:
     case CAIRO_FORMAT_RGB30:
     case CAIRO_FORMAT_INVALID:
     case CAIRO_FORMAT_ARGB32:
-	rowlen = 4 * width;
+	instride = rowlen = 4 * width;
 	break;
     }
     len = rowlen * height;
@@ -2951,7 +2952,7 @@ _image_read_raw (csi_file_t *src,
 		break;
 	    }
 
-	    memset (row + rowlen, 0, stride - rowlen);
+	    memset (row + instride, 0, stride - instride);
 	}
 
 	/* need to treat last row carefully */
@@ -3039,7 +3040,7 @@ _image_read_raw (csi_file_t *src,
 	    /* stride == width */
 	    break;
 	}
-	memset (data + rowlen, 0, stride - rowlen);
+	memset (data + instride, 0, stride - instride);
     } else {
 #ifndef WORDS_BIGENDIAN
 	switch (format) {