[Process] Deprecate using values that are not string for Process::setStdin and ProcessBuilder::setInput

UPGRADE-3.0.md

@@ -971,3 +971,4 @@ UPGRADE FROM 2.x to 3.0
 
  * Process::setStdin() and Process::getStdin() have been removed. Use
    Process::setInput() and Process::getInput() that works the same way.
+ * Process::setInput() and ProcessBuilder::setInput() do not accept non-scalar types.

src/Symfony/Component/Process/CHANGELOG.md

@@ -8,6 +8,7 @@ CHANGELOG
  * added the convenience method "mustRun"
  * deprecation: Process::setStdin() is deprecated in favor of Process::setInput()
  * deprecation: Process::getStdin() is deprecated in favor of Process::getInput()
+ * deprecation: Process::setInput() and ProcessBuilder::setInput() do not accept non-scalar types
 
 2.4.0
 -----

src/Symfony/Component/Process/Process.php

@@ -1060,6 +1060,8 @@ class Process
     /**
      * Sets the contents of STDIN.
      *
+     * Deprecation: As of Symfony 2.5, this method only accepts scalar values.
+     *
      * @param string|null $stdin The new contents
      *
      * @return self The current Process instance

src/Symfony/Component/Process/ProcessBuilder.php

@@ -156,6 +156,8 @@ class ProcessBuilder
     /**
      * Sets the input of the process.
      *
+     * Deprecation: As of Symfony 2.5, this method only accepts string values.
+     *
      * @param string|null $input The input as a string
      *
      * @return ProcessBuilder

src/Symfony/Component/Process/ProcessUtils.php

@@ -75,7 +75,7 @@ class ProcessUtils
     }
 
     /**
-     * Validates and normalized a Process input
+     * Validates and normalizes a Process input
      *
      * @param string $caller The name of method call that validates the input
      * @param mixed  $input  The input to validate
@@ -87,7 +87,11 @@ class ProcessUtils
     public static function validateInput($caller, $input)
     {
         if (null !== $input) {
-            if (is_scalar($input) || (is_object($input) && method_exists($input, '__toString'))) {
+            if (is_scalar($input)) {
+                return (string) $input;
+            }
+            // deprecated as of Symfony 2.5, to be removed in 3.0
+            if (is_object($input) && method_exists($input, '__toString')) {
                 return (string) $input;
             }