From 44f6423c53d8223cba27e21c0f9650e179d38e7a Mon Sep 17 00:00:00 2001
From: Manuel Strehl <com.github@manuel-strehl.de>
Date: Thu, 8 Oct 2015 12:29:43 +0200
Subject: [PATCH] detect isset() and mark found variables declared

If you have code like

    if (isset($foo)) {
        $bar = $foo;
    }

you already guard yourself against undefined variables. In this case the sniff should treat the variable as if it were declared.
---
 Sniffs/CodeAnalysis/VariableAnalysisSniff.php | 34 ++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/Sniffs/CodeAnalysis/VariableAnalysisSniff.php b/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
index e822ad3..bba92af 100644
--- a/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
+++ b/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
@@ -785,7 +785,34 @@ protected function checkForFunctionPrototype(
         }
         return false;
     }
+    
+    /**
+     * isset() marks a variable as declared
+     */
+    protected function checkForIsset(
+        PHP_CodeSniffer_File $phpcsFile,
+        $stackPtr,
+        $varName,
+        $currScope
+    ) {
+        $tokens = $phpcsFile->getTokens();
+        $token  = $tokens[$stackPtr];
+
+        // Are we an isset() parameter?
+        if (($openPtr = $this->findContainingBrackets($phpcsFile, $stackPtr)) === false) {
+            return false;
+        }
 
+        $catchPtr = $phpcsFile->findPrevious(T_WHITESPACE,
+            $openPtr - 1, null, true, null, true);
+        if (($catchPtr !== false) &&
+            ($tokens[$catchPtr]['code'] === T_ISSET)) {
+            $this->markVariableAssignment($varName, $stackPtr, $currScope);
+            return true;
+        }
+        return false;
+    }
+ 
     protected function checkForCatchBlock(
         PHP_CodeSniffer_File $phpcsFile,
         $stackPtr,
@@ -1262,6 +1289,11 @@ protected function processVariable(
             return;
         }
 
+        // Are we an isset() parameter?
+        if ($this->checkForIsset($phpcsFile, $stackPtr, $varName, $currScope)) {
+            return;
+        }
+
         // Are we a catch parameter?
         if ($this->checkForCatchBlock($phpcsFile, $stackPtr, $varName, $currScope)) {
             return;
@@ -1495,4 +1527,4 @@ protected function processScopeClose(
     }
 }//end class
 
-?>
\ No newline at end of file
+?>