Fix a crash in IP address checking because the boundary case for an empty or ...

src/url_canon_ip.cc

Index: src/url_canon_ip.cc
===================================================================
--- src/url_canon_ip.cc	(revision 133)
+++ src/url_canon_ip.cc	(working copy)
@@ -58,11 +58,14 @@
 bool DoFindIPv4Components(const CHAR* spec,
                           const url_parse::Component& host,
                           url_parse::Component components[4]) {
+  if (!host.is_nonempty())
+    return false;
+
   int cur_component = 0;  // Index of the component we're working on.
   int cur_component_begin = host.begin;  // Start of the current component.
   int end = host.end();
   for (int i = host.begin; /* nothing */; i++) {
-    if (i == end || spec[i] == '.') {
+    if (i >= end || spec[i] == '.') {
       // Found the end of the current component.
       int component_len = i - cur_component_begin;
       components[cur_component] =
@@ -79,7 +82,7 @@
       if (component_len == 0 && (i != end || cur_component == 1))

[Peter Kasting, 2010/05/11 18:34:33]

You should change "i != end" to "i < end" here.

         return false;
 
-      if (i == end)
+      if (i >= end)
         break;  // End of the input.
 
       if (cur_component == 4) {