From 49147f95fe3ea03b617c82cb24ec405c317ddbfd Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Mon, 28 Mar 2022 22:15:40 +0200
Subject: [PATCH] Fix #10918 FP constStatement with dynamic_cast (#3954)

---
 lib/checkother.cpp               |  5 ++++-
 test/testincompletestatement.cpp | 11 +++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 812f006dc..58675bbad 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1777,8 +1777,11 @@ static bool isConstStatement(const Token *tok, bool cpp)
         return true;
     if (Token::simpleMatch(tok->previous(), "sizeof ("))
         return true;
-    if (isCPPCast(tok))
+    if (isCPPCast(tok)) {
+        if (Token::simpleMatch(tok->astOperand1(), "dynamic_cast") && Token::simpleMatch(tok->astOperand1()->next()->link()->previous(), "& >"))
+            return false;
         return isWithoutSideEffects(cpp, tok) && isConstStatement(tok->astOperand2(), cpp);
+    }
     else if (tok->isCast() && tok->next() && tok->next()->isStandardType())
         return isWithoutSideEffects(cpp, tok->astOperand1()) && isConstStatement(tok->astOperand1(), cpp);
     if (Token::simpleMatch(tok, "."))
diff --git a/test/testincompletestatement.cpp b/test/testincompletestatement.cpp
index 0e7bdb6bc..3bb3526da 100644
--- a/test/testincompletestatement.cpp
+++ b/test/testincompletestatement.cpp
@@ -283,6 +283,17 @@ private:
               "    ((struct foo *)(0x1234))->xy = 1;\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        check("bool f(const std::exception& e) {\n" // #10918
+              "    try {\n"
+              "        dynamic_cast<const InvalidTypeException&>(e);\n"
+              "        return true;\n"
+              "    }\n"
+              "    catch (...) {\n"
+              "        return false;\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void increment() {