Ticket #42437: 42437.2.diff

src/wp-includes/functions.php

@@ -2425 +2425 @@
         if ( $unique_filename_callback && is_callable( $unique_filename_callback ) ) {
                 $filename = call_user_func( $unique_filename_callback, $dir, $name, $ext );
         } else {
+                // Always append a number to filenames that can potentially match subsize filenames.
+                $ext_esc = preg_quote( $ext );
+                $fname    = pathinfo( $filename, PATHINFO_FILENAME );
+                if ( preg_match( "/-\d+x\d+{$ext_esc}\$/", $filename ) ) {
+                        $number = 1;
+                        while ( file_exists( "{$dir}/{$fname}-{$number}{$ext}" ) ) {
+                                $number++;
+                        }
+
+                        $filename = "{$fname}-{$number}{$ext}";
+                }
+
                 $number = '';
 
                 // Change '.ext' to lower case.
@@ -2440 +2452 @@
                                 $number     = $new_number;
                         }
 
-                        /**
-                         * Filters the result when generating a unique file name.
-                         *
-                         * @since 4.5.0
-                         *
-                         * @param string        $filename                 Unique file name.
-                         * @param string        $ext                      File extension, eg. ".png".
-                         * @param string        $dir                      Directory path.
-                         * @param callable|null $unique_filename_callback Callback function that generates the unique file name.
-                         */
-                        return apply_filters( 'wp_unique_filename', $filename2, $ext, $dir, $unique_filename_callback );
+                        $filename = $filename2;
                 }
-
-                while ( file_exists( $dir . "/$filename" ) ) {
-                        $new_number = (int) $number + 1;
-                        if ( '' == "$number$ext" ) {
-                                $filename = "$filename-" . $new_number;
-                        } else {
-                                $filename = str_replace( array( "-$number$ext", "$number$ext" ), '-' . $new_number . $ext, $filename );
+                else {
+                        while ( file_exists( $dir . "/$filename" ) ) {
+                                $new_number = (int) $number + 1;
+                                if ( '' == "$number$ext" ) {
+                                        $filename = "$filename-" . $new_number;
+                                } else {
+                                        $filename = str_replace( array( "-$number$ext", "$number$ext" ), '-' . $new_number . $ext, $filename );
+                                }
+                                $number = $new_number;
                         }
-                        $number = $new_number;
+                }
+
+                // prevent collisions with existing filenames that contain dimension-like strings (whether they
+                // are subsizes or originals uploaded prior to patch #xxx
+                // the array_filter() calls are similar to glob() but with the full
+                // expressiveness of regular expressions.
+                $number = 0;
+                // get the fname again, in case $filename has been modified above.
+                $fname  = pathinfo( $filename, PATHINFO_FILENAME );
+                $regex = "/^{$fname}-\d+x\d+{$ext_esc}\$/";
+                $files = array_filter( scandir( $dir ), function( $file ) { return ! in_array( $file, array( '.', '..' ) ); } );
+                if ( array_filter( $files, function( $file ) use ( $regex ) { return 1 === preg_match( $regex, $file ); } ) ) {
+                        do {
+                                $number++;
+                                $regex = "/^{$fname}-{$number}-\d+x\d+{$ext_esc}\$/";
+                        } while ( array_filter( $files, function( $file ) use ( $regex ) { return 1 === preg_match( $regex, $file ); } ) );
+
+                        $filename = "{$fname}-{$number}{$ext}";
                 }
         }
 
-        /** This filter is documented in wp-includes/functions.php */
+        /**
+         * Filters the result when generating a unique file name.
+         *
+         * @since 4.5.0
+         *
+         * @param string        $filename                 Unique file name.
+         * @param string        $ext                      File extension, eg. ".png".
+         * @param string        $dir                      Directory path.
+         * @param callable|null $unique_filename_callback Callback function that generates the unique file name.
+         */
         return apply_filters( 'wp_unique_filename', $filename, $ext, $dir, $unique_filename_callback );
 }
 

tests/phpunit/tests/functions.php

@@ -195 +195 @@
                 $this->assertEquals( 'abcdefg.png', wp_unique_filename( $testdir, 'abcde\\\fg.png' ), 'Tripple slashed not removed' );
         }
 
+        /**
+         * @group 42437
+         */
+        function test_unique_filename_with_dimension_like_filename() {
+                $testdir = DIR_TESTDATA . '/images/';
+
+                // test collision with "dimension-like" original filename.
+                $this->assertEquals( 'one-blue-pixel-100x100-1.png', wp_unique_filename( $testdir, 'one-blue-pixel-100x100.png' ) );
+                // test collision with existing sub-size filename.
+                $this->assertEquals( 'one-blue-pixel-1.png', wp_unique_filename( $testdir, 'one-blue-pixel.png' ) );
+        }
+
         function test_is_serialized() {
                 $cases = array(
                         serialize( null ),