Shell: skip null parameters

Right now they're treated as empty strings, however
this doesn't allow skipping parameters in the middle like
 $params = [
     'foo',
     $x ? '--bar' : null,
     '--baz',
 ];

In some cases this matters, e.g. `ls` works while `ls ''` doesn't.

Also, fix spacing problems the new tests uncovered:
* Extra space when using params()
* Missing space when combining params() and unsafeParams()

Change-Id: Icb29d4c48ae7f92fb5635e3865346c98f47abb01

diff --git a/includes/shell/Command.php b/includes/shell/Command.php
index 264c3b4..998b3ed 100644 (file)
--- a/includes/shell/Command.php
+++ b/includes/shell/Command.php
@@ -106,6 +106,7 @@ class Command {
 
        /**
         * Adds parameters to the command. All parameters are sanitized via Shell::escape().
+        * Null values are ignored.
         *
         * @param string|string[] $args,...
         * @return $this
@@ -117,13 +118,14 @@ class Command {
                        // treat it as a list of arguments
                        $args = reset( $args );
                }
-               $this->command .= ' ' . Shell::escape( $args );
+               $this->command = trim( $this->command . ' ' . Shell::escape( $args ) );
 
                return $this;
        }
 
        /**
         * Adds unsafe parameters to the command. These parameters are NOT sanitized in any way.
+        * Null values are ignored.
         *
         * @param string|string[] $args,...
         * @return $this
@@ -135,7 +137,12 @@ class Command {
                        // treat it as a list of arguments
                        $args = reset( $args );
                }
-               $this->command .= implode( ' ', $args );
+               $args = array_filter( $args,
+                       function ( $value ) {
+                               return $value !== null;
+                       }
+               );
+               $this->command = trim( $this->command . ' ' . implode( ' ', $args ) );
 
                return $this;
        }

diff --git a/includes/shell/Shell.php b/includes/shell/Shell.php
index 6e4fd02..084e10e 100644 (file)
--- a/includes/shell/Shell.php
+++ b/includes/shell/Shell.php
@@ -142,7 +142,7 @@ class Shell {
         * PHP 5.2.6+ (bug backported to earlier distro releases of PHP).
         *
         * @param string $args,... strings to escape and glue together, or a single array of
-        *     strings parameter
+        *     strings parameter. Null values are ignored.
         * @return string
         */
        public static function escape( /* ... */ ) {
@@ -156,6 +156,9 @@ class Shell {
                $first = true;
                $retVal = '';
                foreach ( $args as $arg ) {
+                       if ( $arg === null ) {
+                               continue;
+                       }
                        if ( !$first ) {
                                $retVal .= ' ';
                        } else {

diff --git a/tests/phpunit/includes/shell/CommandTest.php b/tests/phpunit/includes/shell/CommandTest.php
index 81fae33..f7275e1 100644 (file)
--- a/tests/phpunit/includes/shell/CommandTest.php
+++ b/tests/phpunit/includes/shell/CommandTest.php
@@ -1,6 +1,7 @@
 <?php
 
 use MediaWiki\Shell\Command;
+use Wikimedia\TestingAccessWrapper;
 
 /**
  * @group Shell
@@ -103,6 +104,16 @@ class CommandTest extends PHPUnit_Framework_TestCase {
                $this->assertRegExp( '/^.+no-such-file.*$/m', $result->getStderr() );
        }
 
+       /**
+        * Test that null values are skipped by params() and unsafeParams()
+        */
+       public function testNullsAreSkipped() {
+               $command = TestingAccessWrapper::newFromObject( new Command );
+               $command->params( 'echo', 'a', null, 'b' );
+               $command->unsafeParams( 'c', null, 'd' );
+               $this->assertEquals( "'echo' 'a' 'b' c d", $command->command );
+       }
+
        public function testT69870() {
                $commandLine = wfIsWindows()
                        // 333 = 331 + CRLF

diff --git a/tests/phpunit/includes/shell/ShellTest.php b/tests/phpunit/includes/shell/ShellTest.php
index 1e91074..7c96c3c 100644 (file)
--- a/tests/phpunit/includes/shell/ShellTest.php
+++ b/tests/phpunit/includes/shell/ShellTest.php
@@ -25,6 +25,7 @@ class ShellTest extends PHPUnit_Framework_TestCase {
                        'simple' => [ [ 'true' ], "'true'" ],
                        'with args' => [ [ 'convert', '-font', 'font name' ], "'convert' '-font' 'font name'" ],
                        'array' => [ [ [ 'convert', '-font', 'font name' ] ], "'convert' '-font' 'font name'" ],
+                       'skip nulls' => [ [ 'ls', null ], "'ls'" ],
                ];
        }
 }