nginx 0.5.20 *) Feature: the "sendfile_max_chunk" directive. *) Feature: the "$http_...", "$sent_http_...", and "$upstream_http_..." variables may be changed using the "set" directive. *) Bugfix: a segmentation fault might occur in worker process if the SSI command 'if expr="$var = /"' was used. *) Bugfix: trailing boundary of multipart range response was transferred incorrectly. Thanks to Evan Miller. *) Bugfix: nginx did not work on Solaris/sparc64 if it was built by Sun Studio. Thanks to Andrei Nigmatulin. *) Bugfix: the ngx_http_perl_module could not built by Solaris make. Thanks to Andrei Nigmatulin.

--- a/src/http/modules/ngx_http_ssi_filter_module.c
+++ b/src/http/modules/ngx_http_ssi_filter_module.c
@@ -2376,7 +2376,7 @@ ngx_http_ssi_if(ngx_http_request_t *r, n
         p++;
     }
 
-    if (p < last && *p == '/') {
+    if (p < last - 1 && *p == '/') {
         if (*(last - 1) != '/') {
             goto invalid_expression;
         }