From 2c2fbaf0e5902d62a4321cdac125778a2170ec5d Mon Sep 17 00:00:00 2001
From: Mariusz Plucinski <plucinski.mariusz@gmail.com>
Date: Wed, 20 Jun 2012 08:02:00 -0400
Subject: [PATCH] Do not crash on unknown source language (#13323)

If a source file extension is not recognized as any language then
src.GetLanguage() may return NULL.  Check the result before
dereferencing in cmLocalGenerator::GetObjectFileNameWithoutTarget.
---
 Source/cmLocalGenerator.cxx | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 13ede5d70..32cfa68cb 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2764,10 +2764,13 @@ cmLocalGenerator
     bool replaceExt = this->NeedBackwardsCompatibility(2, 4);
     if(!replaceExt)
       {
-      std::string repVar = "CMAKE_";
-      repVar += source.GetLanguage();
-      repVar += "_OUTPUT_EXTENSION_REPLACE";
-      replaceExt = this->Makefile->IsOn(repVar.c_str());
+      if(const char* lang = source.GetLanguage())
+        {
+        std::string repVar = "CMAKE_";
+        repVar += lang;
+        repVar += "_OUTPUT_EXTENSION_REPLACE";
+        replaceExt = this->Makefile->IsOn(repVar.c_str());
+        }
       }
 
     // Remove the source extension if it is to be replaced.