From: Tony Cook <tony@develop=help.com>
Date: Thu, 19 Oct 2006 10:26:12 +0000 (+0000)
Subject: The gif_disposal and gif_user_input tags weren't being set to the
X-Git-Tag: Imager-0.55~21
X-Git-Url: http://git.imager.perl.org/imager.git/commitdiff_plain/336f5078205737fd922506cc6378f901cd93e4b3

The gif_disposal and gif_user_input tags weren't being set to the
correct values when a GIF with a GCE block was read.

http://rt.cpan.org/Ticket/Display.html?id=22192
---

diff --git a/gif.c b/gif.c
index 792b8407..a31cc9a0 100644
--- a/gif.c
+++ b/gif.c
@@ -519,12 +519,12 @@ i_img **i_readgif_multi_low(GifFileType *GifFile, int *count, int page) {
   
   GifRowType GifRow;
   int got_gce = 0;
-  int trans_index; /* transparent index if we see a GCE */
-  int gif_delay; /* delay from a GCE */
-  int user_input; /* user input flag from a GCE */
-  int disposal; /* disposal method from a GCE */
+  int trans_index = 0; /* transparent index if we see a GCE */
+  int gif_delay = 0; /* delay from a GCE */
+  int user_input = 0; /* user input flag from a GCE */
+  int disposal = 0; /* disposal method from a GCE */
   int got_ns_loop = 0;
-  int ns_loop;
+  int ns_loop = 0;
   char *comment = NULL; /* a comment */
   i_img **results = NULL;
   int result_alloc = 0;
@@ -748,8 +748,8 @@ i_img **i_readgif_multi_low(GifFileType *GifFile, int *count, int page) {
         else
           trans_index = -1;
         gif_delay = Extension[2] + 256 * Extension[3];
-        user_input = (Extension[0] & 2) != 0;
-        disposal = (Extension[0] >> 2) & 3;
+        user_input = (Extension[1] & 2) != 0;
+        disposal = (Extension[1] >> 2) & 7;
       }
       if (ExtCode == 0xFF && *Extension == 11) {
         if (memcmp(Extension+1, "NETSCAPE2.0", 11) == 0) {
@@ -1660,13 +1660,13 @@ Returns non-zero on success.
 
 static undef_int
 i_writegif_low(i_quantize *quant, GifFileType *gf, i_img **imgs, int count) {
-  unsigned char *result;
+  unsigned char *result = NULL;
   int color_bits;
   ColorMapObject *map;
   int scrw = 0, scrh = 0;
   int imgn, orig_count, orig_size;
   int posx, posy;
-  int trans_index;
+  int trans_index = -1;
   i_mempool mp;
   int *localmaps;
   int anylocal;
@@ -1674,11 +1674,11 @@ i_writegif_low(i_quantize *quant, GifFileType *gf, i_img **imgs, int count) {
   int glob_img_count;
   i_color *orig_colors = quant->mc_colors;
   i_color *glob_colors = NULL;
-  int glob_color_count;
+  int glob_color_count = 0;
   int glob_want_trans;
-  int glob_paletted; /* the global map was made from the image palettes */
-  int colors_paletted;
-  int want_trans;
+  int glob_paletted = 0; /* the global map was made from the image palettes */
+  int colors_paletted = 0;
+  int want_trans = 0;
   int interlace;
   int gif_background;
 
diff --git a/t/t105gif.t b/t/t105gif.t
index a8a7842b..423645c8 100644
--- a/t/t105gif.t
+++ b/t/t105gif.t
@@ -1,4 +1,5 @@
 #!perl -w
+
 =pod
 
 IF THIS TEST CRASHES
@@ -12,7 +13,7 @@ UPGRADE.
 use strict;
 $|=1;
 use lib 't';
-use Test::More tests => 113;
+use Test::More tests => 125;
 use Imager qw(:all);
 BEGIN { require "t/testtools.pl"; }
 use Carp 'confess';
@@ -48,7 +49,7 @@ SKIP:
     $im = Imager->new(xsize=>2, ysize=>2);
     ok(!$im->write(file=>"testout/nogif.gif"), "should fail to write gif");
     is($im->errstr, 'format not supported', "check no gif message");
-    skip("no gif support", 109);
+    skip("no gif support", 121);
   }
     open(FH,">testout/t105.gif") || die "Cannot open testout/t105.gif\n";
     binmode(FH);
@@ -669,6 +670,25 @@ SKIP:
     is($im[0]->tags(name => 'gif_delay'), 50, "first delay read back");
     is($im[1]->tags(name => 'gif_delay'), 50, "second delay read back");
   }
+ SKIP:
+  { # check graphic control extension and ns loop tags are read correctly
+    print "# check GCE and netscape loop extension tag values\n";
+    my @im = Imager->read_multi(file => 'testimg/screen3.gif');
+    is(@im, 2, "read 2 images from screen3.gif")
+      or skip("Could not load testimg/screen3.gif:".Imager->errstr, 11);
+    is($im[0]->tags(name => 'gif_delay'),          50, "0 - gif_delay");
+    is($im[0]->tags(name => 'gif_disposal'),        2, "0 - gif_disposal");
+    is($im[0]->tags(name => 'gif_trans_index'), undef, "0 - gif_trans_index");
+    is($im[0]->tags(name => 'gif_user_input'),      0, "0 - gif_user_input");
+    is($im[0]->tags(name => 'gif_loop'),            0, "0 - gif_loop");
+    is($im[1]->tags(name => 'gif_delay'),          50, "1 - gif_delay");
+    is($im[1]->tags(name => 'gif_disposal'),        2, "1 - gif_disposal");
+    is($im[1]->tags(name => 'gif_trans_index'),     7, "1 - gif_trans_index");
+    is($im[1]->tags(name => 'gif_trans_color'), 'color(255,255,255,0)',
+       "1 - gif_trans_index");
+    is($im[1]->tags(name => 'gif_user_input'),      0, "1 - gif_user_input");
+    is($im[1]->tags(name => 'gif_loop'),            0, "1 - gif_loop");
+  }
 }
 
 sub test_readgif_cb {