Fix #11786 False positive: memory leak (#5182)

lib/checkleakautovar.cpp

@@ -609,7 +609,7 @@ bool CheckLeakAutoVar::checkScope(const Token * const startToken,
         // unknown control.. (TODO: handle loops)
         else if ((Token::Match(tok, "%type% (") && Token::simpleMatch(tok->linkAt(1), ") {")) || Token::simpleMatch(tok, "do {")) {
             varInfo.clear();
-            break;
+            return false;
         }
 
         // return

test/testleakautovar.cpp

@@ -178,6 +178,7 @@ private:
 
         // loops
         TEST_CASE(loop1);
+        TEST_CASE(loop2);
 
         // mismatching allocation/deallocation
         TEST_CASE(mismatchAllocDealloc);
@@ -2070,6 +2071,17 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void loop2() {
+        check("void f() {\n" // #11786
+              "    int* p = (int*)malloc(sizeof(int));\n"
+              "    if (1) {\n"
+              "        while (0) {}\n"
+              "        free(p);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void mismatchAllocDealloc() {
         check("void f() {\n"
               "    FILE*f=fopen(fname,a);\n"