Ticket #32437: 32437.2.diff

src/wp-includes/functions.php

@@ -7296 +7296 @@
 function is_php_version_compatible( $required ) {
         return empty( $required ) || version_compare( phpversion(), $required, '>=' );
 }
+
+/**
+ * Check if two numbers are nearly the same.
+ * 
+ * This is similar to using `round()` but the precision is more fine-grained.
+ *
+ * @since 5.3.0
+ * 
+ * @param int|float $expected  The expected value.
+ * @param int|float $actual    The actual number.
+ * @param int|float $precision The allowed variation.
+ * @return bool Whether the numbers match whithin the specified precision.
+ */
+function wp_fuzzy_number_match( $expected, $actual, $precision = 1 ) {
+        return abs( (float) $expected - (float) $actual ) <= $precision;
+}

src/wp-includes/media.php

@@ -543 +543 @@
                 return $output;
         }
 
+        // Stop if the destination size is larger than the original image dimensions.
+        if ( empty( $dest_h ) ) {
+                if ( $orig_w < $dest_w ) {
+                        return false;
+                }
+        } elseif ( empty( $dest_w ) ) {
+                if ( $orig_h < $dest_h ) {
+                        return false;
+                }
+        } else {
+                if ( $orig_w < $dest_w && $orig_h < $dest_h ) {
+                        return false;
+                }
+        }
+
         if ( $crop ) {
-                // crop the largest possible portion of the original image that we can size to $dest_w x $dest_h
+                // Crop the largest possible portion of the original image that we can size to $dest_w x $dest_h.
+                // Note that the requested crop dimensions are used as a maximum bounding box for the original image.
+                // If the original image's width or height is less than the requested width or height
+                // only the greater one will be cropped.
+                // For example when the original image is 600x300, and the requested crop dimensions are 400x400,
+                // the resulting image will be 400x300.
                 $aspect_ratio = $orig_w / $orig_h;
                 $new_w        = min( $dest_w, $orig_w );
                 $new_h        = min( $dest_h, $orig_h );
@@ -584 +604 @@
                         $s_y = floor( ( $orig_h - $crop_h ) / 2 );
                 }
         } else {
-                // don't crop, just resize using $dest_w x $dest_h as a maximum bounding box
+                // Resize using $dest_w x $dest_h as a maximum bounding box.
                 $crop_w = $orig_w;
                 $crop_h = $orig_h;
 
@@ -594 +614 @@
                 list( $new_w, $new_h ) = wp_constrain_dimensions( $orig_w, $orig_h, $dest_w, $dest_h );
         }
 
-        // if the resulting image would be the same size or larger we don't want to resize it
-        if ( $new_w >= $orig_w && $new_h >= $orig_h && intval( $dest_w ) !== intval( $orig_w ) && intval( $dest_h ) !== intval( $orig_h ) ) {
-                return false;
+        if ( wp_fuzzy_number_match( $new_w, $orig_w ) && wp_fuzzy_number_match( $new_h, $orig_h ) ) {
+                // The new size has virtually the same dimensions as the original image.
+
+                /**
+                 * Filters whether to proceed with making an image sub-size with identical dimensions
+                 * with the original/source image. Differences of 1px may be due to rounding and are ignored.
+                 *
+                 * @since 5.3.0
+                 * 
+                 * @param bool The filtered value.
+                 * @param int  Original image width.
+                 * @param int  Original image height.
+                 */
+                $proceed = (bool) apply_filters( 'wp_image_resize_identical_dimensions', false, $orig_w, $orig_h );
+
+                if ( ! $proceed ) {
+                        return false;
+                }
         }
 
-        // the return array matches the parameters to imagecopyresampled()
+        // The return array matches the parameters to imagecopyresampled().
         // int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h
         return array( 0, 0, (int) $s_x, (int) $s_y, (int) $new_w, (int) $new_h, (int) $crop_w, (int) $crop_h );
-
 }
 
 /**
@@ -664 +698 @@
         }
 
         // If the image dimensions are within 1px of the expected size, we consider it a match.
-        $matched = ( abs( $constrained_size[0] - $expected_size[0] ) <= 1 && abs( $constrained_size[1] - $expected_size[1] ) <= 1 );
+        $matched = ( wp_fuzzy_number_match( $constrained_size[0], $expected_size[0] ) && wp_fuzzy_number_match( $constrained_size[1], $expected_size[1] ) );
 
         return $matched;
 }

tests/phpunit/tests/image/dimensions.php

@@ -131 +131 @@
         function test_640x480() {
                 // crop 640x480 to fit 640x480 (no change)
                 $out = image_resize_dimensions( 640, 480, 640, 480, true );
+                $this->assertFalse( $out );
+
+                // resize 640x480 to fit 640x480 (no change)
+                $out = image_resize_dimensions( 640, 480, 640, 480, false );
+                $this->assertFalse( $out );
+
+                // Test with the filter override.
+                add_filter( 'wp_image_resize_identical_dimensions', '__return_true' );
+
+                // crop 640x480 to fit 640x480 (no change)
+                $out = image_resize_dimensions( 640, 480, 640, 480, true );
                 // dst_x, dst_y, src_x, src_y, dst_w, dst_h, src_w, src_h
                 $this->assertEquals( array( 0, 0, 0, 0, 640, 480, 640, 480 ), $out );
 
@@ -138 +149 @@
                 $out = image_resize_dimensions( 640, 480, 640, 480, false );
                 // dst_x, dst_y, src_x, src_y, dst_w, dst_h, src_w, src_h
                 $this->assertEquals( array( 0, 0, 0, 0, 640, 480, 640, 480 ), $out );
+
+                remove_filter( 'wp_image_resize_identical_dimensions', '__return_true' );
         }
 
         /**