Fix typo correction of one qualified name to another.

When suggesting "foo::bar" as a correction for "fob::bar" we mistakenly
replaced only "bar" with "foo::bar" producing "fob::foo::bar" which was broken.

This corrects that replacement in as many places as I could find & provides
test cases for all those cases I could find a test case for. There are a couple
that don't seem to be reachable (one looks entirely dead, the other just
doesn't seem to ever get called with a namespace to namespace change).

Review by Richard Smith ( http://llvm-reviews.chandlerc.com/D57 ).

llvm-svn: 165817
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index aec5f01..ee246b81 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -435,7 +435,8 @@
       else if (DeclContext *DC = computeDeclContext(*SS, false))
         Diag(IILoc, diag::err_unknown_nested_typename_suggest)
           << II << DC << CorrectedQuotedStr << SS->getRange()
-          << FixItHint::CreateReplacement(SourceRange(IILoc), CorrectedStr);
+          << FixItHint::CreateReplacement(Corrected.getCorrectionRange(),
+                                          CorrectedStr);
       else
         llvm_unreachable("could not have corrected a typo here");
 
@@ -684,11 +685,12 @@
           Diag(NameLoc, UnqualifiedDiag)
             << Name << CorrectedQuotedStr
             << FixItHint::CreateReplacement(NameLoc, CorrectedStr);
-        else
+        else // FIXME: is this even reachable? Test it.
           Diag(NameLoc, QualifiedDiag)
             << Name << computeDeclContext(SS, false) << CorrectedQuotedStr
             << SS.getRange()
-            << FixItHint::CreateReplacement(NameLoc, CorrectedStr);
+            << FixItHint::CreateReplacement(Corrected.getCorrectionRange(),
+                                            CorrectedStr);
 
         // Update the name, so that the caller has the new name.
         Name = Corrected.getCorrectionAsIdentifierInfo();
@@ -4894,6 +4896,10 @@
   }
 
   if (Correction) {
+    // FIXME: use Correction.getCorrectionRange() instead of computing the range
+    // here. This requires passing in the CXXScopeSpec to CorrectTypo which in
+    // turn causes the correction to fully qualify the name. If we fix
+    // CorrectTypo to minimally qualify then this change should be good.
     SourceRange FixItLoc(NewFD->getLocation());
     CXXScopeSpec &SS = ExtraArgs.D.getCXXScopeSpec();
     if (Correction.getCorrectionSpecifier() && SS.isValid())