From 5de683ec498e1eb846fe741cbc21d17aeecd086f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Fri, 2 Nov 2018 20:10:40 +0100
Subject: [PATCH] Container size: Fix false positive

---
 lib/valueflow.cpp      | 9 +++++++++
 test/testvalueflow.cpp | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index fb13b9bca..b1831b518 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -3492,6 +3492,8 @@ static bool hasContainerSizeGuard(const Token *tok, unsigned int containerId)
     return false;
 }
 
+static bool isContainerSizeChanged(unsigned int varId, const Token *start, const Token *end);
+
 static bool isContainerSizeChangedByFunction(const Token *tok)
 {
     const Token *parent = tok->astParent();
@@ -3536,6 +3538,13 @@ static void valueFlowContainerForward(const Token *tok, unsigned int containerId
     while (nullptr != (tok = tok->next())) {
         if (Token::Match(tok, "[{}]"))
             break;
+        if (Token::Match(tok, "while|for (")) {
+            const Token *start = tok->linkAt(1)->next();
+            if (!Token::simpleMatch(start->link(), "{"))
+                break;
+            if (isContainerSizeChanged(containerId, start, start->link()))
+                break;
+        }
         if (tok->varId() != containerId)
             continue;
         if (Token::Match(tok, "%name% ="))
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index ad63b1c3f..350cb66c4 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -3422,6 +3422,14 @@ private:
                "}";
         ASSERT(tokenValues(code, "s [").empty());
 
+        // valueFlowContainerForward, loop
+        code = "void f() {\n"
+               "    std::stack<Token *> links;\n"
+               "    while (!links.empty() || indentlevel)\n"
+               "        links.push(tok);\n"
+               "}";
+        ASSERT(tokenValues(code, "links . empty").empty());
+
         // valueFlowContainerForward, function call
         code = "void f() {\n"
                "  std::list<int> x;\n"