Introduce filter webp_uploads_pre_replace_additional_image_source to short-circuit replacing additional image sources in frontend content

modules/images/webp-uploads/load.php

@@ -486,16 +486,38 @@ function webp_uploads_img_tag_update_mime_type( $image, $context, $attachment_id
 
 		$basename = wp_basename( $metadata['file'] );
 		if ( $basename !== $replacement_source ) {
-			$image = str_replace(
-				$basename,
-				$replacement_source,
-				$image
-			);
+
+			/**
+			 * Filter to replace additional image source file, by locating the original
+			 * mime types of the file and return correct file path in the end.
+			 *
+			 * Altering the $image tag through this filter effectively short-circuits the default replacement logic using the preferred MIME type.
+			 *
+			 * @since n.e.x.t
+			 *
+			 * @param string $image         An <img> tag where the urls would be updated.
+			 * @param int    $attachment_id The ID of the attachment being modified.
+			 * @param string $size          The size name that would be used to create this image, out of the registered subsizes.
+			 * @param string $target_mime   The target mime in which the image should be created.
+			 * @param string $context       The context where this is function is being used.
+			 */
+			$filtered_image = (string) apply_filters( 'webp_uploads_pre_replace_additional_image_source', $image, $attachment_id, 'full', $target_mime, $context );
+
+			// If filtered image is same as the image, run our own replacement logic, otherwise rely on the filtered image.
+			if ( $filtered_image === $image ) {
+				$image = str_replace(
+					$basename,
+					$metadata['sources'][ $target_mime ]['file'],
+					$image
+				);
+			} else {
+				$image = $filtered_image;
+			}
 		}
 	}
 
 	// Replace sub sizes for the image if present.
-	foreach ( $metadata['sizes'] as $name => $size_data ) {
+	foreach ( $metadata['sizes'] as $size => $size_data ) {
 		if ( empty( $size_data['file'] ) ) {
 			continue;
 		}
@@ -518,11 +540,19 @@ function webp_uploads_img_tag_update_mime_type( $image, $context, $attachment_id
 			continue;
 		}
 
-		$image = str_replace(
-			$size_data['file'],
-			$size_data['sources'][ $target_mime ]['file'],
-			$image
-		);
+		/** This filter is documented in modules/images/webp-uploads/load.php */
+		$filtered_image = (string) apply_filters( 'webp_uploads_pre_replace_additional_image_source', $image, $attachment_id, $size, $target_mime, $context );
+
+		// If filtered image is same as the image, run our own replacement logic, otherwise rely on the filtered image.
+		if ( $filtered_image === $image ) {
+			$image = str_replace(
+				$size_data['file'],
+				$size_data['sources'][ $target_mime ]['file'],
+				$image
+			);
+		} else {
+			$image = $filtered_image;
+		}
 	}
 
 	return $image;

tests/modules/images/webp-uploads/load-tests.php

@@ -608,4 +608,27 @@ public function it_should_replace_the_featured_image_to_web_p_when_requesting_th
 		$this->assertStringContainsString( '.webp', $featured_image );
 		$this->assertStringNotContainsString( '.jpeg', $featured_image );
 	}
+
+	/**
+	 * Prevent replacing an image if image was uploaded via external source or plugin.
+	 *
+	 * @group webp_uploads_update_image_references
+	 *
+	 * @test
+	 */
+	public function it_should_prevent_replacing_an_image_uploaded_via_external_source() {
+		remove_all_filters( 'webp_uploads_pre_replace_additional_image_source' );
+
+		add_filter(
+			'webp_uploads_pre_replace_additional_image_source',
+			function() {
+				return '<img src="https://ia600200.us.archive.org/16/items/SPD-SLRSY-1867/hubblesite_2001_06.jpg">';
+			}
+		);
+
+		$attachment_id = $this->factory->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/car.jpeg' );
+
+		$tag = wp_get_attachment_image( $attachment_id, 'medium', false, array( 'class' => "wp-image-{$attachment_id}" ) );
+		$this->assertNotSame( $tag, webp_uploads_img_tag_update_mime_type( $tag, 'the_content', $attachment_id ) );
+	}
 }