Check headers sent before sending PHP response

GromNaN · fabpot · commit 97591c1b309c · 2014-03-26T19:06:50.000+01:00
If the response contents has been sent before an error occurs, PHP
triggers the warning "Cannot modify header information - headers already sent"

This change ensure that the error message is echoed, while it's impossible
to change the HTTP status code and headers.
diff --git a/src/Symfony/Component/Debug/ExceptionHandler.php b/src/Symfony/Component/Debug/ExceptionHandler.php
@@ -91,9 +91,11 @@ public function sendPhpResponse($exception)
             $exception = FlattenException::create($exception);
         }
 
-        header(sprintf('HTTP/1.0 %s', $exception->getStatusCode()));
-        foreach ($exception->getHeaders() as $name => $value) {
-            header($name.': '.$value, false);
+        if (!headers_sent()) {
+            header(sprintf('HTTP/1.0 %s', $exception->getStatusCode()));
+            foreach ($exception->getHeaders() as $name => $value) {
+                header($name.': '.$value, false);
+            }
         }
 
         echo $this->decorate($this->getContent($exception), $this->getStylesheet($exception));

Original file line number	Diff line number	Diff line change
`@@ -91,9 +91,11 @@ public function sendPhpResponse($exception)`
`91`	`91`	`$exception = FlattenException::create($exception);`
`92`	`92`	`}`
`93`	`93`
`94`		`- header(sprintf('HTTP/1.0 %s', $exception->getStatusCode()));`
`95`		`- foreach ($exception->getHeaders() as $name => $value) {`
`96`		`- header($name.': '.$value, false);`
	`94`	`+ if (!headers_sent()) {`
	`95`	`+ header(sprintf('HTTP/1.0 %s', $exception->getStatusCode()));`
	`96`	`+ foreach ($exception->getHeaders() as $name => $value) {`
	`97`	`+ header($name.': '.$value, false);`
	`98`	`+ }`
`97`	`99`	`}`
`98`	`100`
`99`	`101`	`echo $this->decorate($this->getContent($exception), $this->getStylesheet($exception));`