Changeset 52269 for trunk/tests/phpunit/tests/image/functions.php

Timestamp:

11/29/2021 07:34:51 PM (3 years ago)

Author:

hellofromTonya

Message:

Media: Fix TypeError and improve wp_exif_frac2dec() to only return int or float.

For certain images, wp_exif_frac2dec() unexpectedly returned a string instead of int or float. This can occur when an image is missing meta and calls the function with '0/0'. For those images, a fatal error was thrown on PHP 8.0+:

TypeError: round(): Argument #1 ($num) must be of type int|float, string given

Upon deeper review, inconsistent and unexpected results were returned from different types of input values passed to the function.

Changes are:

• Maintains backwards-compatibility for valid input values.
• Fixes handling of invalid input values by bailing out to return the documented type of int|float by returning 0.
• Improves the fractional conditional check.
• Improves the calculated fraction handling to ensure (a) the numerator and denominator are both numeric and (b) the denominator is not equal to zero.
• Safeguards the behavior via tests for all possible ways code could flow through the function.
• Safeguards the backwards-compatibility of the wp_read_image_metadata() by adding some defensive coding around the calls to the wp_exif_frac2dec() function.

These changes fix the fatal error and make the function more secure, stable, and predictable while maintaining backwards-compatibility for valid input values.

Follow-up to [6313], [9119], [22319], [28367], [45611], [47287].

Props adamsilverstein, jrf, peterwilsoncc, praem90, stevegs, tobiasbg.
Fixes #54385.

File:

• trunk/tests/phpunit/tests/image/functions.php (modified) (1 diff)

trunk/tests/phpunit/tests/image/functions.php

@@ -701 +701 @@
         }
     }
+
+    /**
+     * Test for wp_exif_frac2dec verified that it properly handles edge cases
+     * and always returns an int or float, or 0 for failures.
+     *
+     * @param mixed     $fraction The fraction to convert.
+     * @param int|float $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
+     */
+    public function data_wp_exif_frac2dec() {
+        return array(
+            'invalid input: null'              => array(
+                'fraction' => null,
+                'expect'   => 0,
+            ),
+            'invalid input: boolean true'      => array(
+                'fraction' => null,
+                'expect'   => 0,
+            ),
+            'invalid input: empty array value' => array(
+                'fraction' => array(),
+                'expect'   => 0,
+            ),
+            'input is already integer'         => array(
+                'fraction' => 12,
+                'expect'   => 12,
+            ),
+            'input is already float'           => array(
+                'fraction' => 10.123,
+                'expect'   => 10.123,
+            ),
+            'string input is not a fraction - no slash, not numeric' => array(
+                'fraction' => '123notafraction',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - no slash, numeric integer' => array(
+                'fraction' => '48',
+                'expect'   => 48.0,
+            ),
+            'string input is not a fraction - no slash, numeric integer (integer 0)' => array(
+                'fraction' => '0',
+                'expect'   => 0.0,
+            ),
+            'string input is not a fraction - no slash, octal numeric integer' => array(
+                'fraction' => '010',
+                'expect'   => 10.0,
+            ),
+            'string input is not a fraction - no slash, numeric float (float 0)' => array(
+                'fraction' => '0.0',
+                'expect'   => 0.0,
+            ),
+            'string input is not a fraction - no slash, numeric float (typical fnumber)' => array(
+                'fraction' => '4.8',
+                'expect'   => 4.8,
+            ),
+            'string input is not a fraction - more than 1 slash with text' => array(
+                'fraction' => 'path/to/file',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - more than 1 slash with numbers' => array(
+                'fraction' => '1/2/3',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - only a slash' => array(
+                'fraction' => '/',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - only slashes' => array(
+                'fraction' => '///',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - left/right is not numeric' => array(
+                'fraction' => 'path/to',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - left is not numeric' => array(
+                'fraction' => 'path/10',
+                'expect'   => 0,
+            ),
+            'string input is not a fraction - right is not numeric' => array(
+                'fraction' => '0/abc',
+                'expect'   => 0,
+            ),
+            'division by zero is prevented 1'  => array(
+                'fraction' => '0/0',
+                'expect'   => 0,
+            ),
+            'division by zero is prevented 2'  => array(
+                'fraction' => '100/0.0',
+                'expect'   => 0,
+            ),
+            'typical focal length'             => array(
+                'fraction' => '37 mm',
+                'expect'   => 0,
+            ),
+            'typical exposure time'            => array(
+                'fraction' => '1/350',
+                'expect'   => 0.002857142857142857,
+            ),
+            'valid fraction 1'                 => 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,
+            ),
+        );
+    }
 }