From 025881cf35fdde1299d16a09059e7305f8c9bd13 Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Mon, 17 Dec 2018 06:07:34 +0100
Subject: [PATCH]  Fix issue 8829: Condition '...' is always true (int buf[42];
 if(buf != NULL){})

This makes arrays non-null in valueflow, so it can catch comparisons against null that is always true:

```cpp
void f(void) {
   int buf[42];
   if( buf != 0) {;} // << always true
}
```
---
 lib/checkio.cpp        | 8 +++++---
 lib/valueflow.cpp      | 6 ++++++
 test/testcondition.cpp | 6 ++++++
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index 73ca0006a..acdf2fa79 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -472,9 +472,11 @@ static bool findFormat(unsigned int arg, const Token *firstArg,
                  argTok->variable()->dimension(0) != 0))) {
         *formatArgTok = argTok->nextArgument();
         if (!argTok->values().empty()) {
-            const ValueFlow::Value &value = argTok->values().front();
-            if (value.isTokValue() && value.tokvalue && value.tokvalue->tokType() == Token::eString) {
-                *formatStringTok = value.tokvalue;
+            std::list<ValueFlow::Value>::const_iterator value = std::find_if(
+                        argTok->values().begin(), argTok->values().end(), std::mem_fn(&ValueFlow::Value::isTokValue));
+            if (value != argTok->values().end() && value->isTokValue() && value->tokvalue &&
+                value->tokvalue->tokType() == Token::eString) {
+                *formatStringTok = value->tokvalue;
             }
         }
         return true;
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index e0fc45d05..6117cdb05 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -1001,6 +1001,12 @@ static void valueFlowArray(TokenList *tokenlist)
 
     for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
         if (tok->varId() > 0U) {
+            // array
+            if (tok->variable() && tok->variable()->isArray() && !tok->variable()->isStlType()) {
+                ValueFlow::Value value{1};
+                value.setKnown();
+                setTokenValue(tok, value, tokenlist->getSettings());
+            }
             const std::map<unsigned int, const Token *>::const_iterator it = constantArrays.find(tok->varId());
             if (it != constantArrays.end()) {
                 ValueFlow::Value value;
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 10772ee53..8984f282e 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -2520,6 +2520,12 @@ private:
         check("void f1(const std::string &s) { if(s.empty()) if(s.size() == 0) {}} ");
         ASSERT_EQUALS("[test.cpp:1] -> [test.cpp:1]: (style) Condition 's.size()==0' is always true\n", errout.str());
 
+        check("void f() {\n"
+              "   int buf[42];\n"
+              "   if( buf != 0) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Condition 'buf!=0' is always true\n", errout.str());
+
         // Avoid FP when condition comes from macro
         check("#define NOT !\n"
               "void f() {\n"