From 3e6540c4b392d47bd6f70c0ee0312564a65851a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 31 Oct 2021 14:47:52 +0100
Subject: [PATCH] Fixed #10523 (FP: missingReturn with nested switch
 statements)

---
 lib/checkfunctions.cpp | 12 ++++++++----
 test/testfunctions.cpp | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 802fd94ba..87f200bdb 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -303,9 +303,13 @@ static const Token *checkMissingReturnScope(const Token *tok, const Library &lib
                 // find reachable break / !default
                 bool hasDefault = false;
                 bool reachable = false;
-                for (const Token *switchToken = tok->link(); switchToken != tok; switchToken = switchToken->next()) {
-                    if (reachable && Token::simpleMatch(switchToken, "break ;"))
-                        return switchToken;
+                for (const Token *switchToken = tok->link()->next(); switchToken != tok; switchToken = switchToken->next()) {
+                    if (reachable && Token::simpleMatch(switchToken, "break ;")) {
+                        if (Token::simpleMatch(switchToken->previous(), "}") && !checkMissingReturnScope(switchToken->previous(), library))
+                            reachable = false;
+                        else
+                            return switchToken;
+                    }
                     if (switchToken->isKeyword() && Token::Match(switchToken, "return|throw"))
                         reachable = false;
                     if (Token::Match(switchToken, "%name% (") && library.isnoreturn(switchToken))
@@ -314,7 +318,7 @@ static const Token *checkMissingReturnScope(const Token *tok, const Library &lib
                         reachable = true;
                     if (Token::simpleMatch(switchToken, "default :"))
                         hasDefault = true;
-                    else if (switchToken->str() == "{" && switchToken->scope()->isLoopScope())
+                    else if (switchToken->str() == "{" && (switchToken->scope()->isLoopScope() || switchToken->scope()->type == Scope::ScopeType::eSwitch))
                         switchToken = switchToken->link();
                 }
                 if (!hasDefault)
diff --git a/test/testfunctions.cpp b/test/testfunctions.cpp
index eae150925..9eca6b483 100644
--- a/test/testfunctions.cpp
+++ b/test/testfunctions.cpp
@@ -1441,6 +1441,20 @@ private:
               "}");
         ASSERT_EQUALS("", errout.str());
 
+        check("bool test(unsigned char v1, int v2) {\n"
+              "    switch (v1) {\n"
+              "        case 0:\n"
+              "            switch (v2) {\n"
+              "            case 48000:\n"
+              "                break;\n"
+              "            }\n"
+              "            return false;\n"
+              "        default:\n"
+              "            return true;\n"
+              "    }\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+
         // if/else
         check("int f(int x) {\n"
               "    if (x) {\n"