From a64669b1ecb58480f5177a61eaaf12845c9f32d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 30 Sep 2012 17:22:35 +0200
Subject: [PATCH] Fixed #4203 (Don't warn about setting NULL value for pointers
 and not using that value)

---
 .travis.yml            |  2 +-
 lib/checkunusedvar.cpp |  2 +-
 test/testunusedvar.cpp | 11 +++++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 7f6d1f054..a2b6281ee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,4 +5,4 @@ compiler:
 script:
   - make test
   - $CXX -o cppcheck -O2 cli/*.cpp lib/*.cpp -Ilib
-  - ./cppcheck --error-exitcode=1 -Ilib --enable=style --suppress=unreadVariable --suppress=duplicateBranch --suppress=stlIfStrFind -q cli gui lib -igui/test
+  - ./cppcheck --error-exitcode=1 -Ilib --enable=style --suppress=duplicateBranch --suppress=stlIfStrFind -q cli gui lib -igui/test
diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 095298b65..31baf351e 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -250,7 +250,7 @@ void Variables::write(unsigned int varid, const Token* tok)
 
     if (usage) {
         usage->_write = true;
-        if (!usage->_var->isStatic())
+        if (!usage->_var->isStatic() && !Token::simpleMatch(tok->next(), "= 0 ;"))
             usage->_read = false;
         usage->_lastAccess = tok;
     }
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index fbccd5e97..c895c719e 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -144,6 +144,7 @@ private:
         TEST_CASE(localvarIfNOT);    // #3104 - if ( NOT var )
         TEST_CASE(localvarAnd);      // #3672
         TEST_CASE(localvarSwitch);   // #3744 - false positive when localvar is used in switch
+        TEST_CASE(localvarNULL);     // #4203 - Setting NULL value is not redundant - it is safe
 
         TEST_CASE(crash1);
     }
@@ -3317,6 +3318,16 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvarNULL() { // #4203 - Setting NULL value is not redundant - it is safe
+        functionVariableUsage("void f() {\n"
+                              "    char *p = malloc(100);\n"
+                              "    foo(p);\n"
+                              "    free(p);\n"
+                              "    p = NULL;\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void crash1() {
         functionVariableUsage("SAL_WNODEPRECATED_DECLARATIONS_PUSH\n"
                               "void convertToTokenArray() {\n"