When the mime is different from source, add the extension to the suff…

…ix to ensure uniqueness

src/wp-admin/includes/image.php

@@ -703,9 +703,10 @@ function _wp_make_additional_mime_types( $new_mime_types, $file, $image_meta, $a
 			continue;
 		}
 
-		$suffix = _wp_get_image_suffix( $resized, $rotated );
+		$suffix    = _wp_get_image_suffix( $resized, $rotated );
+		$extension = wp_get_default_extension_for_mime_type( $mime_type );
 
-		$saved = $editor->save( $editor->generate_filename( $suffix ) );
+		$saved = $editor->save( $editor->generate_filename( $suffix, null, $extension ) );
 
 		if ( is_wp_error( $saved ) ) {
 			// TODO: Log errors.

src/wp-includes/class-wp-image-editor-gd.php

@@ -476,18 +476,6 @@ protected function _save( $image, $filename = null, $mime_type = null ) {
 			$filename = $this->generate_filename( null, null, $extension );
 		}
 
-		// Skip already existing files that don't belong to this image attachment.
-		if ( file_exists( $filename ) ) {
-			// Get the url of the image file.
-			$uploads_dir   = wp_upload_dir();
-			$file_url      = str_replace( $uploads_dir['basedir'], $uploads_dir()['baseurl'], $this->file );
-			$attachment_id = attachment_url_to_postid( $file_url );
-
-			if ( $attachment_id && ! _wp_image_belongs_to_attachment( wp_basename( $filename ), $attachment_id ) ) {
-				return new WP_Error( 'image_save_error', __( 'Image Editor Save Failed' ) );
-			}
-		}
-
 		if ( 'image/gif' === $mime_type ) {
 			if ( ! $this->make_image( $filename, 'imagegif', array( $image, $filename ) ) ) {
 				return new WP_Error( 'image_save_error', __( 'Image Editor Save Failed' ) );

src/wp-includes/class-wp-image-editor-imagick.php

@@ -718,18 +718,6 @@ protected function _save( $image, $filename = null, $mime_type = null ) {
 			$filename = $this->generate_filename( null, null, $extension );
 		}
 
-		// Skip already existing files that don't belong to this image attachment.
-		if ( file_exists( $filename ) ) {
-			// Get the url of the image file.
-			$uploads_dir   = wp_upload_dir();
-			$file_url      = str_replace( $uploads_dir['basedir'], $uploads_dir()['baseurl'], $this->file );
-			$attachment_id = attachment_url_to_postid( $file_url );
-
-			if ( $attachment_id && ! _wp_image_belongs_to_attachment( wp_basename( $filename ), $attachment_id ) ) {
-				return new WP_Error( 'image_save_error', __( 'Image Editor Save Failed' ) );
-			}
-		}
-
 		try {
 			// Store initial format.
 			$orig_format = $this->image->getImageFormat();

src/wp-includes/class-wp-image-editor.php

@@ -471,6 +471,11 @@ public function generate_filename( $suffix = null, $dest_path = null, $extension
 			$suffix = "-{$suffix}";
 		}
 
+		// When the mime type being generated is different from the source, add the extension to the suffix to ensure uniqueness.
+		if ( ! empty( $extension ) && $extension !== $ext ) {
+			$suffix .= "-{$ext}";
+		}
+
 		return trailingslashit( $dir ) . "{$name}{$suffix}.{$new_ext}";
 	}