nginx 0.7.60 *) Feature: the "updating" parameter in "proxy_cache_use_stale" and "fastcgi_cache_use_stale" directives. *) Feature: the "keepalive_requests" directive. *) Bugfix: in open_file_cache and proxy/fastcgi cache interaction on start up. *) Bugfix: open_file_cache might cache open file descriptors too long. *) Bugfix: the "If-Modified-Since", "If-Range", etc. client request header lines were passed to backend while caching if no "proxy_set_header" directive was used with any parameters. *) Bugfix: the "Set-Cookie" and "P3P" response header lines were not hidden while caching if no "proxy_hide_header/fastcgi_hide_header" directives were used with any parameters. *) Bugfix: the ngx_http_image_filter_module did not support GIF87a format. Thanks to Denis Ilyinyh. *) Bugfix: nginx could not be built modules on Solaris 10 and early; the bug had appeared in 0.7.56. *) Bugfix: XLST filter did not work in subrequests. *) Bugfix: in relative paths handling in nginx/Windows. *) Bugfix: in proxy_store, fastcgi_store, proxy_cache, and fastcgi_cache in nginx/Windows.

--- a/src/http/modules/ngx_http_image_filter_module.c
+++ b/src/http/modules/ngx_http_image_filter_module.c
@@ -383,11 +383,12 @@ ngx_http_image_test(ngx_http_request_t *
         return NGX_HTTP_IMAGE_JPEG;
 
     } else if (p[0] == 'G' && p[1] == 'I' && p[2] == 'F' && p[3] == '8'
-               && p[4] == '9' && p[5] == 'a')
+               && p[5] == 'a')
     {
-        /* GIF */
-
-        return NGX_HTTP_IMAGE_GIF;
+        if (p[4] == '9' || p[4] == '7') {
+            /* GIF */
+            return NGX_HTTP_IMAGE_GIF;
+        }
 
     } else if (p[0] == 0x89 && p[1] == 'P' && p[2] == 'N' && p[3] == 'G'
                && p[4] == 0x0d && p[5] == 0x0a && p[6] == 0x1a && p[7] == 0x0a)