From 510748134f9cf4217020acc95e4a72b481a27d81 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 4 Aug 2019 10:21:16 +0200
Subject: [PATCH] Fixed #9234 (FP unreadVariable - assignment via iterator)

---
 lib/checkunusedvar.cpp |  6 ++++++
 test/testunusedvar.cpp | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index efb6b8793..553d84375 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -1174,6 +1174,12 @@ void CheckUnusedVar::checkFunctionVariableUsage()
             if (!tok->astOperand1())
                 continue;
 
+            const Token *iteratorToken = tok->astOperand1();
+            while (Token::Match(iteratorToken, "[.*]"))
+                iteratorToken = iteratorToken->astOperand1();
+            if (iteratorToken && iteratorToken->variable() && iteratorToken->variable()->typeEndToken()->str().find("iterator") != std::string::npos)
+                continue;
+
             const Variable *op1Var = tok->astOperand1() ? tok->astOperand1()->variable() : nullptr;
             if (op1Var && op1Var->isReference() && op1Var->nameToken() != tok->astOperand1())
                 // todo: check references
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index 274bda174..11249d389 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -129,6 +129,7 @@ private:
         TEST_CASE(localvaralias15); // ticket #6315
         TEST_CASE(localvaralias16);
         TEST_CASE(localvaralias17); // ticket #8911
+        TEST_CASE(localvaralias18); // ticket #9234 - iterator
         TEST_CASE(localvarasm);
         TEST_CASE(localvarstatic);
         TEST_CASE(localvarextern);
@@ -3217,6 +3218,22 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvaralias18() {
+        functionVariableUsage("void add( std::vector< std::pair< int, double > >& v)\n"
+                              "{\n"
+                              "    std::vector< std::pair< int, double > >::iterator it;\n"
+                              "    for ( it = v.begin(); it != v.end(); ++it )\n"
+                              "    {\n"
+                              "        if ( x )\n"
+                              "        {\n"
+                              "            ( *it ).second = 0;\n"
+                              "            break;\n"
+                              "        }\n"
+                              "    }\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvarasm() {
 
         functionVariableUsage("void foo(int &b)\n"