Fix #12966 FN returnDanglingLifetime with std::span and array (regression) (#6660)

Author: chrchr-github

lib/valueflow.cpp

@@ -3278,7 +3278,7 @@ static bool isDecayedPointer(const Token *tok)
         return true;
     if (!Token::simpleMatch(tok->astParent(), "return"))
         return false;
-    return astIsPointer(tok->astParent());
+    return astIsPointer(tok->astParent()) || astIsContainerView(tok->astParent());
 }
 
 static bool isConvertedToView(const Token* tok, const Settings& settings)

test/testautovariables.cpp

@@ -3048,6 +3048,14 @@ class TestAutoVariables : public TestFixture {
         ASSERT_EQUALS(
             "[test.cpp:4] -> [test.cpp:4] -> [test.cpp:6]: (error) Using object that points to local variable 'v' that is out of scope.\n",
             errout_str());
+
+        check("std::span<const int> f() {\n" // #12966
+              "    int a[10]{};\n"
+              "    return a;\n"
+              "}\n");
+        ASSERT_EQUALS(
+            "[test.cpp:3] -> [test.cpp:2] -> [test.cpp:3]: (error) Returning pointer to local variable 'a' that will be invalid when returning.\n",
+            errout_str());
     }
 
     void danglingLifetimeUniquePtr()