[include-fixer] Don't add qualifiers in missing complete type cases.

[hokein]

Summary

In missing complete type cases, we don't know where to add the qualifiers.

include-fixer/IncludeFixer.cpp

bool MaybeDiagnoseMissingCompleteType(clang::SourceLocation Loc,
     if (getCompilerInstance().getSema().isSFINAEContext())
       return false;
 
     clang::ASTContext &context = getCompilerInstance().getASTContext();
     std::string QueryString =
         T.getUnqualifiedType().getAsString(context.getPrintingPolicy());
     DEBUG(llvm::dbgs() << "Query missing complete type '" << QueryString
                        << "'");
+    // Pass an empty range here since we don't add qualifier in this case.
     query(QueryString, "", tooling::Range());
     return false;
   }
 
   /// Callback for unknown identifiers. Try to piece together as much
   /// qualification as we can get and do a query.
   clang::TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,
                                     int LookupKind, Scope *S, CXXScopeSpec *SS,
clang::tooling::Replacements Insertions = {
       tooling::Replacement(FilePath, UINT_MAX, 0, IncludeName)};
 
   auto CleanReplaces = cleanupAroundReplacements(Code, Insertions, Style);
   if (!CleanReplaces)
     return CleanReplaces;
 
   if (AddQualifiers) {
     for (const auto &Info : Context.getQuerySymbolInfos()) {
+      // Ignore the empty range.
+      if (Info.Range.getLength() > 0)
         CleanReplaces->insert({FilePath, Info.Range.getOffset(),
                                Info.Range.getLength(),
                                Context.getHeaderInfos().front().QualifiedName});
     }
   }
   return formatReplacements(Code, *CleanReplaces, Style);
 }
 
 } // namespace include_fixer
 } // namespace clang

unittests/include-fixer/IncludeFixerTest.cpp

namespace c {
   bar b;
 } // namespace c
 } // namespace a
 )";
 
   EXPECT_EQ(ExpectedCode, runIncludeFixer(TestCode));
 }
 
+TEST(IncludeFixer, DontAddQualifiersForMissingCompleteType) {
+  EXPECT_EQ("#include \"bar.h\"\nclass bar;\nvoid f() {\nbar* b;\nb->f();\n}",
+            runIncludeFixer("class bar;\nvoid f() {\nbar* b;\nb->f();\n}"));
+}
+
 } // namespace
 } // namespace include_fixer
 } // namespace clang