Fix #14234 FN selfAssignment with global scope operator (#7934)

Author: chrchr-github

lib/astutils.cpp

@@ -1615,10 +1615,14 @@ bool isSameExpression(bool macro, const Token *tok1, const Token *tok2, const Se
         return false;
 
     const Token *followTok1 = tok1, *followTok2 = tok2;
-    while (Token::simpleMatch(followTok1, "::") && followTok1->astOperand2())
-        followTok1 = followTok1->astOperand2();
-    while (Token::simpleMatch(followTok2, "::") && followTok2->astOperand2())
-        followTok2 = followTok2->astOperand2();
+    while (Token::simpleMatch(followTok1, "::"))
+        followTok1 = followTok1->astOperand2() ? followTok1->astOperand2() : followTok1->astOperand1();
+    if (!followTok1)
+        followTok1 = tok1; // TODO: remove after #14235 has been fixed
+    while (Token::simpleMatch(followTok2, "::"))
+        followTok2 = followTok2->astOperand2() ? followTok2->astOperand2() : followTok2->astOperand1();
+    if (!followTok2)
+        followTok2 = tok2;
     if (isSameConstantValue(macro, followTok1, followTok2))
         return true;
 

test/testother.cpp

@@ -6401,6 +6401,10 @@ class TestOther : public TestFixture {
               "    s.i = o;\n"
               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        check("int N;\n" // #14234
+              "void f() { ::N = N; }\n");
+        ASSERT_EQUALS("[test.cpp:2:16]: (style) Redundant assignment of '::N' to itself. [selfAssignment]\n", errout_str());
     }
 
     void trac1132() {