From 905615e99197275d6f59f7f7fa0698d5cb2afb81 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 9 Jun 2012 08:43:13 +0200
Subject: [PATCH] Fixed #3878 (Sign extension with unsigned char false
 positive)

---
 lib/checkother.cpp   | 2 +-
 test/testcharvar.cpp | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 97533d86d..9f35c0128 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1794,7 +1794,7 @@ void CheckOther::checkCharVariable()
 
         else if (Token::Match(tok, "[;{}] %var% = %any% [&^|] ( * %var% ) ;")) {
             const Variable* var = symbolDatabase->getVariableFromVarId(tok->tokAt(7)->varId());
-            if (!var || !var->isPointer() || var->typeStartToken()->str() != "char")
+            if (!var || !var->isPointer() || var->typeStartToken()->str() != "char" || var->typeStartToken()->isUnsigned())
                 continue;
             // it's ok with a bitwise and where the other operand is 0xff or less..
             if (tok->strAt(4) == "&" && tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
diff --git a/test/testcharvar.cpp b/test/testcharvar.cpp
index 4a6c0623f..7f985e3f0 100644
--- a/test/testcharvar.cpp
+++ b/test/testcharvar.cpp
@@ -212,6 +212,14 @@ private:
               "    return ret;\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // #3878 - false positive
+        check("int f(unsigned char *p) {\n"
+              "    int ret = a();\n"
+              "    ret |= *p;\n"
+              "    return ret;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 };