Ticket #54385: 54385.13.diff

src/wp-admin/includes/image.php

@@ -646 +646 @@
  *
  * @since 2.5.0
  *
- * @param string $str
- * @return int|float
+ * @param string $str Fraction string.
+ * @return string|int|float Returns calculated fraction or originally passed string on failure.
  */
 function wp_exif_frac2dec( $str ) {
-        if ( false === strpos( $str, '/' ) ) {
+        // Fractions must contain a single `/`.
+        if ( ! is_scalar( $str ) || substr_count( $str, '/' ) !== 1 ) {
                 return $str;
         }
 
         list( $numerator, $denominator ) = explode( '/', $str );
-        if ( ! empty( $denominator ) ) {
-                return $numerator / $denominator;
+
+        // Both the numerator and the denominator must be numbers.
+        if ( ! is_numeric( $numerator ) || ! is_numeric( $denominator ) ) {
+                return $str;
         }
-        return $str;
+
+        // The denominator must not be zero.
+        if ( empty( $denominator ) ) {
+                return $str;
+        }
+
+        return $numerator / $denominator;
 }
 
 /**
@@ -841 +850 @@
                         $meta['copyright'] = trim( $exif['Copyright'] );
                 }
                 if ( ! empty( $exif['FNumber'] ) ) {
-                        $meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
+                        $meta['aperture'] = round( (float) wp_exif_frac2dec( $exif['FNumber'] ), 2 );
                 }
                 if ( ! empty( $exif['Model'] ) ) {
                         $meta['camera'] = trim( $exif['Model'] );

tests/phpunit/tests/image/functions.php

@@ -700 +700 @@
                         unlink( $temp_dir . $size['file'] );
                 }
         }
+
+        /**
+         * Test for wp_exif_frac2dec verified that it properly handles edge cases
+         * and always returns an int or float, or original value for failures.
+         *
+         * @param string $fraction The fraction to convert.
+         * @param string $expect   The expected result.
+         *
+         * @ticket 54385
+         * @dataProvider data_wp_exif_frac2dec
+         *
+         * @covers ::wp_exif_frac2dec
+         */
+        public function test_wp_exif_frac2dec( $fraction, $expect ) {
+                $this->assertSame( $expect, wp_exif_frac2dec( $fraction ) );
+        }
+
+        /**
+         * Data provider for testing `wp_exif_frac2dec()`.
+         *
+         * @return array {
+         *     Arguments for testing `wp_exif_frac2dec()`.
+         */
+        public function data_wp_exif_frac2dec() {
+                return array(
+                        'division by zero is prevented'         => array(
+                                'fraction' => '0/0',
+                                'expect'   => '0/0',
+                        ),
+                        'division by zero is prevented 2'       => array(
+                                'fraction' => '100/0',
+                                'expect'   => '100/0',
+                        ),
+                        'typical fnumber'                       => array(
+                                'fraction' => '4.8',
+                                'expect'   => '4.8',
+                        ),
+                        'typical focal length'                  => array(
+                                'fraction' => '37 mm',
+                                'expect'   => '37 mm',
+                        ),
+                        'typical exposure time'                 => array(
+                                'fraction' => '1/350',
+                                'expect'   => 0.002857142857142857,
+                        ),
+                        'division by text prevented'            => array(
+                                'fraction' => '0/abc',
+                                'expect'   => '0/abc',
+                        ),
+                        'non fraction returns original value'   => array(
+                                'fraction' => '0.0',
+                                'expect'   => '0.0',
+                        ),
+                        'non fraction returns original value 2' => array(
+                                'fraction' => '010',
+                                'expect'   => '010',
+                        ),
+                        'non fraction returns original value 3' => array(
+                                'fraction' => 10.123,
+                                'expect'   => 10.123,
+                        ),
+                        'valid fraction'                        => array(
+                                'fraction' => '50/100',
+                                'expect'   => 0.5,
+                        ),
+                        'valid fraction 2'                      => array(
+                                'fraction' => '25/100',
+                                'expect'   => .25,
+                        ),
+                        'valid fraction 3'                      => array(
+                                'fraction' => '4/2',
+                                'expect'   => 2,
+                        ),
+                        'non fraction returns original value'   => array(
+                                'fraction' => '0',
+                                'expect'   => '0',
+                        ),
+                        'text is prevented'                     => array(
+                                'fraction' => 'path/to/file',
+                                'expect'   => 'path/to/file',
+                        ),
+                        'text is prevented 2'                   => array(
+                                'fraction' => '123notafraction',
+                                'expect'   => '123notafraction',
+                        ),
+                        'invalid input prevented'               => array(
+                                'fraction' => '/',
+                                'expect'   => '/',
+                        ),
+                        'invalid input prevented 2'             => array(
+                                'fraction' => '1/2/3',
+                                'expect'   => '1/2/3',
+                        ),
+                        'invalid input prevented 3'             => array(
+                                'fraction' => '///',
+                                'expect'   => '///',
+                        ),
+                        'null value'                            => array(
+                                'fraction' => null,
+                                'expect'   => null,
+                        ),
+                        'empty array value'                     => array(
+                                'fraction' => array(),
+                                'expect'   => array(),
+                        ),
+                );
+        }
 }