From 8dcea26c10b854a2ad150157d227d1765a14fd70 Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Sat, 4 Dec 2021 05:55:56 -0600
Subject: [PATCH] Find iterator mismatch when using temporary containers
 (#3579)

---
 lib/checkstl.cpp | 16 ++++++++++++----
 test/teststl.cpp | 21 +++++++++++++++++----
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 77ba95fae..7c4661aae 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -344,9 +344,14 @@ void CheckStl::iteratorsError(const Token* tok, const Token* containerTok, const
 void CheckStl::iteratorsError(const Token* tok, const Token* containerTok, const std::string& containerName)
 {
     std::list<const Token*> callstack = { tok, containerTok };
-    reportError(callstack, Severity::error, "iterators3",
-                "$symbol:" + containerName + "\n"
-                "Same iterator is used with containers '" + containerName + "' that are defined in different scopes.", CWE664, Certainty::normal);
+    reportError(callstack,
+                Severity::error,
+                "iterators3",
+                "$symbol:" + containerName +
+                "\n"
+                "Same iterator is used with containers '$symbol' that are temporaries or defined in different scopes.",
+                CWE664,
+                Certainty::normal);
 }
 
 // Error message used when dereferencing an iterator that has been erased..
@@ -709,8 +714,11 @@ static bool isSameIteratorContainerExpression(const Token* tok1,
                                               const Library& library,
                                               ValueFlow::Value::LifetimeKind kind = ValueFlow::Value::LifetimeKind::Iterator)
 {
-    if (isSameExpression(true, false, tok1, tok2, library, false, false))
+    if (isSameExpression(true, false, tok1, tok2, library, false, false)) {
+        if (astIsContainerOwned(tok1) && isTemporary(true, tok1, &library))
+            return false;
         return true;
+    }
     if (kind == ValueFlow::Value::LifetimeKind::Address) {
         return isSameExpression(true, false, getAddressContainer(tok1), getAddressContainer(tok2), library, false, false);
     }
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 65190f140..2609fd599 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -1305,7 +1305,9 @@ private:
               "        }\n"
               "    }\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:7] -> [test.cpp:4]: (error) Same iterator is used with containers 'l1' that are defined in different scopes.\n", errout.str());
+        ASSERT_EQUALS(
+            "[test.cpp:7] -> [test.cpp:4]: (error) Same iterator is used with containers 'l1' that are temporaries or defined in different scopes.\n",
+            errout.str());
 
         check("void foo()\n"
               "{\n"
@@ -1320,7 +1322,7 @@ private:
               "}");
         TODO_ASSERT_EQUALS(
             "[test.cpp:7] -> [test.cpp:4]: (error) Same iterator is used with containers 'l1' that are defined in different scopes.\n",
-            "[test.cpp:7] -> [test.cpp:7]: (error) Same iterator is used with containers 'l1' that are defined in different scopes.\n[test.cpp:7]: (error) Dangerous comparison using operator< on iterator.\n",
+            "[test.cpp:7] -> [test.cpp:7]: (error) Same iterator is used with containers 'l1' that are temporaries or defined in different scopes.\n[test.cpp:7]: (error) Dangerous comparison using operator< on iterator.\n",
             errout.str());
 
         check("void foo()\n"
@@ -1336,7 +1338,7 @@ private:
               "    }\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:8] -> [test.cpp:4]: (error) Same iterator is used with containers 'l1' that are defined in different scopes.\n",
+            "[test.cpp:8] -> [test.cpp:4]: (error) Same iterator is used with containers 'l1' that are temporaries or defined in different scopes.\n",
             errout.str());
 
         check("void foo()\n"
@@ -1352,7 +1354,18 @@ private:
               "    }\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:8] -> [test.cpp:7]: (error) Same iterator is used with containers 'l1' that are defined in different scopes.\n",
+            "[test.cpp:8] -> [test.cpp:7]: (error) Same iterator is used with containers 'l1' that are temporaries or defined in different scopes.\n",
+            errout.str());
+
+        check("std::set<int> g() {\n"
+              "    static const std::set<int> s = {1};\n"
+              "    return s;\n"
+              "}\n"
+              "void f() {\n"
+              "    if (g().find(2) == g().end()) {}\n"
+              "}\n");
+        ASSERT_EQUALS(
+            "[test.cpp:6] -> [test.cpp:6]: (error) Same iterator is used with containers 'g()' that are temporaries or defined in different scopes.\n",
             errout.str());
     }