From 853d56030b8f236b1efd33378c07f981a4375b40 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 26 Apr 2014 11:27:58 +0200
Subject: [PATCH] Fixed #5559 (false positive: (error) Possible null pointer
 dereference: pSTRunner)

---
 lib/valueflow.cpp      |  9 ++++++++-
 test/testvalueflow.cpp | 10 ++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 87a4c0e9c..edbfd4c17 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -531,6 +531,7 @@ static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger,
         int indentlevel = 0;
         unsigned int number_of_if = 0;
         int varusagelevel = -1;
+        bool returnStatement = false;  // current statement is a return, stop analysis at the ";"
 
         for (Token *tok2 = tok; tok2 && tok2 != endToken; tok2 = tok2->next()) {
             if (indentlevel >= 0 && tok2->str() == "{")
@@ -611,12 +612,18 @@ static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger,
                     tok2 = tok2->linkAt(2);
             }
 
-            else if (Token::Match(tok2, "break|continue")) {
+            else if (indentlevel <= 0 && Token::Match(tok2, "break|continue")) {
                 if (settings->debugwarnings)
                     bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + ". noreturn conditional scope.");
                 break;
             }
 
+            else if (indentlevel <= 0 && tok2->str() == "return")
+                returnStatement = true;
+
+            else if (returnStatement && tok2->str() == ";")
+                break;
+
             if (tok2->varId() == varid) {
                 // bailout: assignment
                 if (Token::Match(tok2->previous(), "!!* %var% =")) {
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 16ca334be..c4cf88551 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -613,6 +613,16 @@ private:
                "}";
         ASSERT_EQUALS(false, testValueOfX(code, 6U, 0));
 
+        code = "void f () {\n"
+               "    ST * x =  g_pST;\n"
+               "    if (x->y == 0) {\n"
+               "        x = NULL;\n"
+               "        return 1;\n"
+               "    }\n"
+               "    a = x->y;\n"
+               "}";
+        ASSERT_EQUALS(false, testValueOfX(code, 7U, 0));
+
         // multivariables
         code = "void f(int a) {\n"
                "    int x = a;\n"