Fix #11741 FP knownConditionTrueFalse minus/negation confuses check (#5766)

Author: chrchr-github

lib/valueflow.cpp

@@ -6304,7 +6304,7 @@ struct ConditionHandler {
                 values.insert(values.end(), cond.false_values.cbegin(), cond.false_values.cend());
 
             // extra logic for unsigned variables 'i>=1' => possible value can also be 0
-            if (Token::Match(tok, "<|>")) {
+            if (Token::Match(tok, "<|>|<=|>=")) {
                 values.remove_if([](const ValueFlow::Value& v) {
                     if (v.isIntValue())
                         return v.intvalue != 0;

test/testcondition.cpp

@@ -4547,6 +4547,14 @@ class TestCondition : public TestFixture {
               "  }\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("int f(int i) {\n" // #11741
+              "    i = -i - 1;\n"
+              "    if (i < 0 || i >= 20)\n"
+              "        return 0;\n"
+              "    return 1;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void alwaysTrueSymbolic()

test/testvalueflow.cpp

@@ -1460,7 +1460,7 @@ class TestValueFlow : public TestFixture {
                "    int a = x;\n"
                "    if (x >= 1) {}\n"
                "}";
-        ASSERT_EQUALS(true, testValueOfX(code, 2U, 1));
+        TODO_ASSERT_EQUALS(true, false, testValueOfX(code, 2U, 1));
         ASSERT_EQUALS(true, testValueOfX(code, 2U, 0));
 
         code = "void f(unsigned int x) {\n"