Fix #12732 FP knownConditionTrueFalse with switch (regression)

Author: chrchr-github

Diff for: lib/forwardanalyzer.cpp

@@ -614,7 +614,7 @@ namespace {
                     const Scope* scope = tok->scope();
                     if (!scope)
                         return Break();
-                    if (contains({Scope::eDo, Scope::eFor, Scope::eWhile, Scope::eIf, Scope::eElse}, scope->type)) {
+                    if (contains({Scope::eDo, Scope::eFor, Scope::eWhile, Scope::eIf, Scope::eElse, Scope::eSwitch}, scope->type)) {
                         const bool inElse = scope->type == Scope::eElse;
                         const bool inDoWhile = scope->type == Scope::eDo;
                         const bool inLoop = contains({Scope::eDo, Scope::eFor, Scope::eWhile}, scope->type);

Diff for: test/testcondition.cpp

@@ -4607,6 +4607,19 @@ class TestCondition : public TestFixture {
               "    if (q) {}\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:4]: (style) Condition 'q' is always true\n", errout_str());
+
+        check("void f(int i) {\n" 
+              "    int j = 0;\n"
+              "    switch (i) {\n"
+              "    case 1:\n"
+              "        j = 0;\n"
+              "        break;\n"
+              "    default:\n"
+              "        j = 1;\n"
+              "    }\n"
+              "    if (j != 0) {}\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void alwaysTrueSymbolic()