[include-fixer] Don't add qualifiers to symbols which have global scope operator.

[bkramer]

This looks like the right thing to do to me.

[hokein]

Rebase to master.

include-fixer/IncludeFixerContext.h

Headers.erase(std::unique(Headers.begin(), Headers.end(),
                   Headers.end());
   }
 
   /// \brief Create a replacement for adding missing namespace qualifiers to the
   /// symbol.
   tooling::Replacement createSymbolReplacement(llvm::StringRef FilePath,
                                                size_t Idx = 0) {
     assert(Idx < MatchedSymbols.size());
+    // No need to add missing qualifiers if SymbolIndentifer has a global scope
+    // operator "::".
+    if (getSymbolIdentifier().startswith("::"))
+      return tooling::Replacement();
     std::string QualifiedName = MatchedSymbols[Idx].getQualifiedName();
     // For nested classes, the qualified name constructed from database misses
     // some stripped qualifiers, because when we search a symbol in database,
     // we strip qualifiers from the end until we find a result. So append the
     // missing stripped qualifiers here.
     //
     // Get stripped qualifiers.
     llvm::SmallVector<llvm::StringRef, 8> SymbolQualifiers;

unittests/include-fixer/IncludeFixerTest.cpp

EXPECT_EQ("#include \"bar.h\"\nnamespace c {\na::b::bar b;\n}\n",
             runIncludeFixer("namespace c {\nbar b;\n}\n"));
 
   // Test nested classes.
   EXPECT_EQ("#include \"bar.h\"\nnamespace c {\na::b::bar::t b;\n}\n",
             runIncludeFixer("namespace c {\nbar::t b;\n}\n"));
   EXPECT_EQ("#include \"bar.h\"\nnamespace a {\nb::bar::t b;\n}\n",
             runIncludeFixer("namespace a {\nbar::t b;\n}\n"));
 
-  EXPECT_EQ(
-      "#include \"color.h\"\nint test = a::b::Green;\n",
+  EXPECT_EQ("#include \"color.h\"\nint test = a::b::Green;\n",
             runIncludeFixer("int test = Green;\n"));
   EXPECT_EQ("#include \"color.h\"\nnamespace d {\nint test = a::b::Green;\n}\n",
             runIncludeFixer("namespace d {\nint test = Green;\n}\n"));
   EXPECT_EQ("#include \"color.h\"\nnamespace a {\nint test = b::Green;\n}\n",
             runIncludeFixer("namespace a {\nint test = Green;\n}\n"));
 
-  // FIXME: Fix-namespace should not fix the global qualified identifier.
-  EXPECT_EQ(
-      "#include \"bar.h\"\na::b::bar b;\n",
+  // Test global scope operator.
+  EXPECT_EQ("#include \"bar.h\"\n::a::b::bar b;\n",
             runIncludeFixer("::a::b::bar b;\n"));
+  EXPECT_EQ("#include \"bar.h\"\nnamespace a {\n::a::b::bar b;\n}\n",
+            runIncludeFixer("namespace a {\n::a::b::bar b;\n}\n"));
 }
 
 } // namespace
 } // namespace include_fixer
 } // namespace clang