Fix crash on ternary with omitted operand (#4673)

* Fix MSVC compiler warning

* Fix crash on incomplete ternary operator

* Revert "Fix crash on incomplete ternary operator"

This reverts commit 28df0f0.

* Handle ternary with omitted operand

Author: chrchr-github

lib/valueflow.cpp

@@ -1744,6 +1744,8 @@ static bool isConvertedToIntegral(const Token* tok, const Settings* settings)
 
 static bool isSameToken(const Token* tok1, const Token* tok2)
 {
+    if (!tok1 || !tok2)
+        return false;
     if (tok1->exprId() != 0 && tok1->exprId() == tok2->exprId())
         return true;
     if (tok1->hasKnownIntValue() && tok2->hasKnownIntValue())

test/testcmdlineparser.cpp

@@ -1265,7 +1265,7 @@ class TestCmdlineParser : public TestFixture {
     void valueFlowMaxIterations() {
         REDIRECT;
         const char * const argv[] = {"cppcheck", "--valueflow-max-iterations=0"};
-        settings.valueFlowMaxIterations = -1;
+        settings.valueFlowMaxIterations = SIZE_MAX;
         ASSERT(defParser.parseFromArgs(2, argv));
         ASSERT_EQUALS(0, settings.valueFlowMaxIterations);
         ASSERT_EQUALS("", GET_REDIRECT_OUTPUT);
@@ -1274,7 +1274,7 @@ class TestCmdlineParser : public TestFixture {
     void valueFlowMaxIterations2() {
         REDIRECT;
         const char * const argv[] = {"cppcheck", "--valueflow-max-iterations=11"};
-        settings.valueFlowMaxIterations = -1;
+        settings.valueFlowMaxIterations = SIZE_MAX;
         ASSERT(defParser.parseFromArgs(2, argv));
         ASSERT_EQUALS(11, settings.valueFlowMaxIterations);
         ASSERT_EQUALS("", GET_REDIRECT_OUTPUT);

test/testvalueflow.cpp

@@ -6839,6 +6839,12 @@ class TestValueFlow : public TestFixture {
                "    std::shared_ptr<B> m;\n"
                "};\n";
         valueOfTok(code, "r");
+
+        code = "void g(int);\n"
+               "void f(int x, int y) {\n"
+               "    g(x < y ? : 1);\n"
+               "};\n";
+        valueOfTok(code, "?");
     }
 
     void valueFlowHang() {