Clang: Fix dot-arrow-correction for zero results

If there are no completion items, do not add snippets since these will
otherwise pop-up at undesired positions, e.g. when:

 1) Typing float/doubles: 0.
 2) Typing file suffix in include directives: #include "stdio.

Task-number: QTCREATORBUG-16188
Change-Id: Ie1c29826dc62dc447b2ff57b0c5537eb9d9511ef
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/clangcodemodel/test/clangcodecompletion_test.cpp

@@ -932,18 +932,28 @@ void ClangCodeCompletionTest::testCompleteConstructorAndFallbackToGlobalCompleti
     QVERIFY(!hasSnippet(t.proposal, "class"));
 }
 
+// Explicitly Inserting The Dot
+// ----------------------------
+// Inserting the dot for is important since it will send the editor
+// content to the backend and thus generate an unsaved file on the backend
+// side. The unsaved file enables us to do the dot to arrow correction.
+
 void ClangCodeCompletionTest::testCompleteWithDotToArrowCorrection()
 {
-    // Inserting the dot for this test is important since it will send the editor
-    // content to the backend and thus generate an unsaved file on the backend
-    // side. The unsaved file enables us to do the dot to arrow correction.
-
     ProjectLessCompletionTest t("dotToArrowCorrection.cpp",
-                                QStringLiteral("."));
+                                QStringLiteral(".")); // See above "Explicitly Inserting The Dot"
 
     QVERIFY(hasItem(t.proposal, "member"));
 }
 
+void ClangCodeCompletionTest::testDontCompleteWithDotToArrowCorrectionForFloats()
+{
+    ProjectLessCompletionTest t("noDotToArrowCorrectionForFloats.cpp",
+                                QStringLiteral(".")); // See above "Explicitly Inserting The Dot"
+
+    QCOMPARE(t.proposal->size(), 0);
+}
+
 void ClangCodeCompletionTest::testCompleteProjectDependingCode()
 {
     const TestDocument testDocument("completionWithProject.cpp");