From 0510d9a2b0c849e606cf19bc8301b1221e84ee3b Mon Sep 17 00:00:00 2001
From: Erik Lax <erik@datahack.se>
Date: Sat, 15 May 2010 19:46:42 +0200
Subject: [PATCH] Fixed #1680 (Bad iterators checks fail to detect invalidation
 of iterator for deletion by value)

---
 lib/checkstl.cpp |  9 +++++++++
 lib/checkstl.h   |  2 ++
 test/teststl.cpp | 13 +++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 8f025b6b7..317ad3161 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -46,6 +46,11 @@ void CheckStl::dereferenceErasedError(const Token *tok, const std::string &itern
     reportError(tok, Severity::error, "eraseDereference", "Dereferenced iterator '" + itername + "' has been erased");
 }
 
+void CheckStl::eraseByValueError(const Token *tok, const std::string &containername, const std::string &itername)
+{
+    reportError(tok, Severity::error, "eraseByValue", "Iterator '" +  itername + "' becomes invalid when deleted by value from '" + containername +  "'");
+}
+
 void CheckStl::iterators()
 {
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
@@ -111,6 +116,10 @@ void CheckStl::iterators()
                 dereferenceErasedError(tok2, tok2->strAt(0));
                 tok2 = tok2->tokAt(2);
             }
+            else if (Token::Match(tok2, "%var% . erase ( * %varid%", iteratorId) && tok2->varId() == containerId)
+            {
+                eraseByValueError(tok2, tok2->strAt(0), tok2->strAt(5));
+            }
         }
     }
 }
diff --git a/lib/checkstl.h b/lib/checkstl.h
index b1a1e32c1..2de554d6c 100644
--- a/lib/checkstl.h
+++ b/lib/checkstl.h
@@ -124,6 +124,7 @@ private:
     void stlBoundriesError(const Token *tok, const std::string &container_name);
     void if_findError(const Token *tok, bool str);
     void sizeError(const Token *tok);
+    void eraseByValueError(const Token *tok, const std::string &containername, const std::string &itername);
 
     void getErrorMessages()
     {
@@ -139,6 +140,7 @@ private:
         if_findError(0, false);
         if_findError(0, true);
         sizeError(0);
+        eraseByValueError(0, "container", "iterator");
     }
 
     std::string name() const
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 9b09b52be..4a051b1b7 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -56,6 +56,7 @@ private:
         TEST_CASE(eraseGoto);
         TEST_CASE(eraseAssign);
         TEST_CASE(eraseErase);
+        TEST_CASE(eraseByValue);
 
         TEST_CASE(pushback1);
         TEST_CASE(pushback2);
@@ -475,6 +476,18 @@ private:
         ASSERT_EQUALS("[test.cpp:6]: (error) Invalid iterator: iter\n", errout.str());
     }
 
+    void eraseByValue()
+    {
+        check("void f()\n"
+              "{\n"
+              "    std::set<int> foo;\n"
+              "    for (std::set<int> it = foo.begin(); it != foo.end(); ++it)\n"
+              "    {\n"
+              "        foo.erase(*it);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:6]: (error) Iterator 'it' becomes invalid when deleted by value from 'foo'\n", errout.str());
+    }
 
 
     void pushback1()