Fix #73155: imagegd2() writes wrong chunk sizes on boundaries

diff --git a/NEWS b/NEWS
index b9ef512bd2a195b024e598a107d5fea11e6bbff5..c0cefbae205552a694cfd9e4558719476bf4d20f 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -27,6 +27,7 @@ PHP                                                                        NEWS
   . Fixed bug #53504 (imagettfbbox gives incorrect values for bounding box).
     (Mark Plomer, cmb)
   . Fixed bug #73157 (imagegd2() ignores 3rd param if 4 are given). (cmb)
+  . Fixed bug #73155 (imagegd2() writes wrong chunk sizes on boundaries). (cmb)
 
 - Mbstring:
   . Fixed bug #72994 (mbc_to_code() out of bounds read). (Laruence, cmb)

diff --git a/ext/gd/libgd/gd_gd2.c b/ext/gd/libgd/gd_gd2.c
index e954aafa6800d7af9147a421bf7f8645e8b6e942..3b4dfbe098a6056242fbdcf4f63267f261042001 100644 (file)
--- a/ext/gd/libgd/gd_gd2.c
+++ b/ext/gd/libgd/gd_gd2.c
@@ -689,8 +689,8 @@ static void _gdImageGd2 (gdImagePtr im, gdIOCtx * out, int cs, int fmt)
        }
 
        /* Work out number of chunks. */
-       ncx = im->sx / cs + 1;
-       ncy = im->sy / cs + 1;
+       ncx = (im->sx + cs - 1) / cs;
+       ncy = (im->sy + cs - 1) / cs;
 
        /* Write the standard header. */
        _gd2PutHeader (im, out, cs, fmt, ncx, ncy);

diff --git a/ext/gd/tests/bug73155.phpt b/ext/gd/tests/bug73155.phpt
new file mode 100644 (file)
index 0000000..dc1791e
--- /dev/null
+++ b/ext/gd/tests/bug73155.phpt
@@ -0,0 +1,28 @@
+--TEST--
+Bug #73155 (imagegd2() writes wrong chunk sizes on boundaries)
+--SKIPIF--
+<?php
+if (!extension_loaded('gd')) die('skip gd extension not available');
+?>
+--FILE--
+<?php
+$im = imagecreate(64, 64);
+imagecolorallocate($im, 0, 0, 0);
+
+ob_start();
+imagegd2($im, null, 64, IMG_GD2_RAW);
+$buffer = ob_get_clean();
+
+$header = unpack('@10/nchunk_size/nformat/nx_count/ny_count', $buffer);
+printf("chunk size: %d\n", $header['chunk_size']);
+printf("x chunk count: %d\n", $header['x_count']);
+printf("y chunk count: %d\n", $header['y_count']);
+printf("file size: %d\n", strlen($buffer));
+?>
+===DONE===
+--EXPECT--
+chunk size: 64
+x chunk count: 1
+y chunk count: 1
+file size: 5145
+===DONE===