symfony
diff --git a/‎src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
Copy file name to clipboardExpand all lines: src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
+1-1Lines changed: 1 addition & 1 deletion b/‎src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
Copy file name to clipboardExpand all lines: src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
+1-1Lines changed: 1 addition & 1 deletion
diff --git a/‎src/Symfony/Component/VarDumper/Dumper/CliDumper.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/VarDumper/Dumper/CliDumper.php
+32-4Lines changed: 32 additions & 4 deletions b/‎src/Symfony/Component/VarDumper/Dumper/CliDumper.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/VarDumper/Dumper/CliDumper.php
+32-4Lines changed: 32 additions & 4 deletions
@@ -404,7 +404,7 @@ private static function hasColorSupport()
         }
 
         if (!self::isTty()) {
-            return true;
+            return false;
         }
 
         if ('\\' === \DIRECTORY_SEPARATOR
 
@@ -610,10 +610,8 @@ private function hasColorSupport($stream): bool
             return false;
         }
 
-        // Detect msysgit/mingw and assume this is a tty because detection
-        // does not work correctly, see https://github.com/composer/composer/issues/9690
-        if (!@stream_isatty($stream) && !\in_array(strtoupper((string) getenv('MSYSTEM')), ['MINGW32', 'MINGW64'], true)) {
-            return true;
+        if (!self::isTty()) {
+            return false;
         }
 
         if ('\\' === \DIRECTORY_SEPARATOR && @sapi_windows_vt100_support($stream)) {
@@ -636,6 +634,36 @@ private function hasColorSupport($stream): bool
         return preg_match('/^((screen|xterm|vt100|vt220|putty|rxvt|ansi|cygwin|linux).*)|(.*-256(color)?(-bce)?)$/', $term);
     }
 
+    /**
+     * Checks if the stream is a TTY, i.e; whether the output stream is connected to a terminal.
+     *
+     * Reference: Composer\Util\Platform::isTty
+     * https://github.com/composer/composer
+     */
+    private static function isTty(): bool
+    {
+        // Detect msysgit/mingw and assume this is a tty because detection
+        // does not work correctly, see https://github.com/composer/composer/issues/9690
+        if (\in_array(strtoupper((string) getenv('MSYSTEM')), ['MINGW32', 'MINGW64'], true)) {
+            return true;
+        }
+
+        // Modern cross-platform function, includes the fstat fallback so if it is present we trust it
+        if (\function_exists('stream_isatty')) {
+            return @stream_isatty(\STDOUT);
+        }
+
+        // Only trusting this if it is positive, otherwise prefer fstat fallback.
+        if (\function_exists('posix_isatty') && @posix_isatty(\STDOUT)) {
+            return true;
+        }
+
+        $stat = @fstat(\STDOUT);
+
+        // Check if formatted mode is S_IFCHR
+        return $stat ? 0020000 === ($stat['mode'] & 0170000) : false;
+    }
+
     /**
      * Returns true if the Windows terminal supports true color.
      *
Original file line number	Diff line number	Diff line change
`@@ -404,7 +404,7 @@ private static function hasColorSupport()`
`404`	`404`	`}`
`405`	`405`
`406`	`406`	`if (!self::isTty()) {`
`407`		`- return true;`
	`407`	`+ return false;`
`408`	`408`	`}`
`409`	`409`
`410`	`410`	`if ('\\' === \DIRECTORY_SEPARATOR`