Fix ParseCIDRBlock() to no longer accept invalid inputs.

net/base/ip_address.cc

Index: net/base/ip_address.cc
diff --git a/net/base/ip_address.cc b/net/base/ip_address.cc
index 42071e010e358be1b30e46431574de9e5dd116f2..701dc3621e5528452bb109b55b665bb231271bc8 100644
--- a/net/base/ip_address.cc
+++ b/net/base/ip_address.cc
@@ -158,9 +158,13 @@ bool ParseCIDRBlock(const std::string& cidr_literal,
   if (!ip_address->AssignFromIPLiteral(parts[0]))
     return false;
 
+  const base::StringPiece& prefix_length = parts[1];

[eroman, 2016/03/21 17:28:31]

Can you add a TODO linking to crbug.com/596523 ?

This is a fine solution for this instance, but I think we want to make a bigger
change to address the other cases.

[martijnc, 2016/03/21 18:29:04]

Done.

+  if (prefix_length.starts_with("+"))
+    return false;
+
   // Parse the prefix length.
   int number_of_bits = -1;
-  if (!base::StringToInt(parts[1], &number_of_bits))
+  if (!base::StringToInt(prefix_length, &number_of_bits))
     return false;
 
   // Make sure the prefix length is in a valid range.