Fixed #3598 (false positive: (error) Memory pointed to by 'a' is freed twice.)

Author: zblair

lib/checkother.cpp

@@ -2501,7 +2501,7 @@ void CheckOther::checkDoubleFree()
 
 
         // If a variable is passed to a function, remove it from the set of previously freed variables
-        else if (Token::Match(tok, "%var% (") && !Token::Match(tok, "printf|sprintf|snprintf|fprintf|if|while")) {
+        else if (Token::Match(tok, "%var% (") && !Token::Match(tok, "printf|sprintf|snprintf|fprintf")) {
 
             // If this is a new function definition, clear all variables
             if (Token::simpleMatch(tok->next()->link(), ") {")) {
@@ -2533,7 +2533,7 @@ void CheckOther::checkDoubleFree()
 
         // Any control statements in-between delete, free() or closedir() statements
         // makes it unclear whether any subsequent statements would be redundant.
-        if (Token::Match(tok, "else|break|continue|goto|return|throw")) {
+        if (Token::Match(tok, "if|else|for|while|break|continue|goto|return|throw|switch")) {
             freedVariables.clear();
             closeDirVariables.clear();
         }

test/testother.cpp

@@ -4614,6 +4614,22 @@ class TestOther : public TestFixture {
             "}"
         );
         ASSERT_EQUALS("", errout.str());
+
+        check(
+            "int foo()\n"
+            "{\n"
+            "	int* a = new int;\n"
+            "	bool doDelete = true;\n"
+            "	if (a != 0)\n"
+            "	{\n"
+            "		doDelete = false;\n"
+            "		delete a;\n"
+            "	}\n"
+            "	if(doDelete)\n"
+            "		delete a;\n"
+            "	return 0;\n"
+            "}"
+        );
     }
 
     void coutCerrMisusage() {