Fix #8235 false positive: memory leak (realloc) (#6394)

Author: chrchr-github

lib/checkleakautovar.cpp

@@ -401,7 +401,7 @@ bool CheckLeakAutoVar::checkScope(const Token * const startToken,
             if (Token::simpleMatch(tokAssignOp->astOperand1(), "."))
                 continue;
             // taking address of another variable..
-            if (Token::Match(tokAssignOp, "= %var% [+;]")) {
+            if (Token::Match(tokAssignOp, "= %var% +|;|?|%comp%")) {
                 if (varTok->tokAt(2)->varId() != varTok->varId()) {
                     // If variable points at allocated memory => error
                     leakIfAllocated(varTok, varInfo);

test/testleakautovar.cpp

@@ -83,6 +83,7 @@ class TestLeakAutoVar : public TestFixture {
         TEST_CASE(assign23);
         TEST_CASE(assign24); // #7440
         TEST_CASE(assign25);
+        TEST_CASE(assign26);
 
         TEST_CASE(isAutoDealloc);
 
@@ -620,6 +621,20 @@ class TestLeakAutoVar : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void assign26() {
+        check("void f(int*& x) {\n" // #8235
+              "    int* p = (int*)malloc(10);\n"
+              "    x = p ? p : nullptr;\n"
+              "}", true);
+        ASSERT_EQUALS("", errout_str());
+
+        check("void f(int*& x) {\n"
+              "    int* p = (int*)malloc(10);\n"
+              "    x = p != nullptr ? p : nullptr;\n"
+              "}", true);
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void isAutoDealloc() {
         check("void f() {\n"
               "    char *p = new char[100];"