Fix #12858 FP knownConditionTrueFalse with switch in try/catch in subfunction (#6553)

Author: chrchr-github

lib/forwardanalyzer.cpp

@@ -811,6 +811,7 @@ namespace {
                 } else if (Token::simpleMatch(tok, "switch (")) {
                     if (updateRecursive(tok->next()->astOperand2()) == Progress::Break)
                         return Break();
+                    actions |= Analyzer::Action::Write; // bailout for switch scope
                     return Break();
                 } else if (Token* callTok = callExpr(tok)) {
                     // TODO: Dont traverse tokens a second time

test/testcondition.cpp

@@ -4632,6 +4632,26 @@ class TestCondition : public TestFixture {
               "        return;\n"
               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        check("int h();\n"
+              "bool g() {\n"
+              "    bool b{};\n"
+              "    try {\n"
+              "        int x = h();\n"
+              "        switch (x) {\n"
+              "        default:\n"
+              "            b = true;\n"
+              "        }\n"
+              "    }\n"
+              "    catch (...) {\n"
+              "        b = false;\n"
+              "    }\n"
+              "    return b;\n"
+              "}\n"
+              "void f() {\n"
+              "    if (g()) {}\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void alwaysTrueSymbolic()