[include-fixer] Make search handle fully qualified names correctly.

If a search string starts with "::" we don't want to return any results
for suffixes of that string.

Differential Revision: http://reviews.llvm.org/D20424

llvm-svn: 270055
diff --git a/clang-tools-extra/unittests/include-fixer/IncludeFixerTest.cpp b/clang-tools-extra/unittests/include-fixer/IncludeFixerTest.cpp
index 101c3e9..64ce283 100644
--- a/clang-tools-extra/unittests/include-fixer/IncludeFixerTest.cpp
+++ b/clang-tools-extra/unittests/include-fixer/IncludeFixerTest.cpp
@@ -103,6 +103,12 @@
   // too.
   EXPECT_EQ("#include <string>\n\nstring foo;\n",
             runIncludeFixer("string foo;\n"));
+
+  // Fully qualified name.
+  EXPECT_EQ("#include <string>\n\n::std::string foo;\n",
+            runIncludeFixer("::std::string foo;\n"));
+  // Should not match std::string.
+  EXPECT_EQ("::string foo;\n", runIncludeFixer("::string foo;\n"));
 }
 
 TEST(IncludeFixer, IncompleteType) {