diff --git a/wp-admin/custom-header.php b/wp-admin/custom-header.php
index 7629af3d3a..12288430cd 100644
--- a/wp-admin/custom-header.php
+++ b/wp-admin/custom-header.php
@@ -663,8 +663,8 @@ wp_nonce_field( 'custom-header-options', '_wpnonce-custom-header-options' ); ?>
 			list( $width, $height, $type, $attr ) = getimagesize( $file );
 		} else {
 			$data = wp_get_attachment_metadata( $attachment_id );
-			$height = $data[ 'height' ];
-			$width = $data[ 'width' ];
+			$height = isset( $data[ 'height' ] ) ? $data[ 'height' ] : 0;
+			$width = isset( $data[ 'width' ] ) ? $data[ 'width' ] : 0;
 			unset( $data );
 		}
 
diff --git a/wp-admin/includes/image-edit.php b/wp-admin/includes/image-edit.php
index b24d4f4a4c..22e209511c 100644
--- a/wp-admin/includes/image-edit.php
+++ b/wp-admin/includes/image-edit.php
@@ -13,7 +13,7 @@ function wp_image_editor($post_id, $msg = false) {
 	$sub_sizes = isset($meta['sizes']) && is_array($meta['sizes']);
 	$note = '';
 
-	if ( is_array($meta) && isset($meta['width']) )
+	if ( isset( $meta['width'], $meta['height'] ) )
 		$big = max( $meta['width'], $meta['height'] );
 	else
 		die( __('Image data does not exist. Please re-upload the image.') );
@@ -21,8 +21,9 @@ function wp_image_editor($post_id, $msg = false) {
 	$sizer = $big > 400 ? 400 / $big : 1;
 
 	$backup_sizes = get_post_meta( $post_id, '_wp_attachment_backup_sizes', true );
-	$can_restore = !empty($backup_sizes) && isset($backup_sizes['full-orig'])
-		&& $backup_sizes['full-orig']['file'] != basename($meta['file']);
+	$can_restore = false;
+	if ( ! empty( $backup_sizes ) && isset( $backup_sizes['full-orig'], $meta['file'] ) )
+		$can_restore = $backup_sizes['full-orig']['file'] != basename( $meta['file'] );
 
 	if ( $msg ) {
 		if ( isset($msg->error) )
@@ -63,8 +64,8 @@ function wp_image_editor($post_id, $msg = false) {
 	<input type="hidden" id="imgedit-history-<?php echo $post_id; ?>" value="" />
 	<input type="hidden" id="imgedit-undone-<?php echo $post_id; ?>" value="0" />
 	<input type="hidden" id="imgedit-selection-<?php echo $post_id; ?>" value="" />
-	<input type="hidden" id="imgedit-x-<?php echo $post_id; ?>" value="<?php echo $meta['width']; ?>" />
-	<input type="hidden" id="imgedit-y-<?php echo $post_id; ?>" value="<?php echo $meta['height']; ?>" />
+	<input type="hidden" id="imgedit-x-<?php echo $post_id; ?>" value="<?php echo isset( $meta['width'] ) ? $meta['width'] : 0; ?>" />
+	<input type="hidden" id="imgedit-y-<?php echo $post_id; ?>" value="<?php echo isset( $meta['height'] ) ? $meta['height'] : 0; ?>" />
 
 	<div id="imgedit-crop-<?php echo $post_id; ?>" class="imgedit-crop-wrap">
 	<img id="image-preview-<?php echo $post_id; ?>" onload="imageEdit.imgLoaded('<?php echo $post_id; ?>')" src="<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>?action=imgedit-preview&amp;_ajax_nonce=<?php echo $nonce; ?>&amp;postid=<?php echo $post_id; ?>&amp;rand=<?php echo rand(1, 99999); ?>" />
@@ -82,9 +83,11 @@ function wp_image_editor($post_id, $msg = false) {
 		<a class="imgedit-help-toggle" onclick="imageEdit.toggleHelp(this);return false;" href="#"><strong><?php _e('Scale Image'); ?></strong></a>
 		<div class="imgedit-help">
 		<p><?php _e('You can proportionally scale the original image. For best results the scaling should be done before performing any other operations on it like crop, rotate, etc. Note that if you make the image larger it may become fuzzy.'); ?></p>
+		<?php if ( isset( $meta['width'], $meta['height'] ) ): ?>
 		<p><?php printf( __('Original dimensions %s'), $meta['width'] . '&times;' . $meta['height'] ); ?></p>
+		<?php endif ?>
 		<div class="imgedit-submit">
-		<span class="nowrap"><input type="text" id="imgedit-scale-width-<?php echo $post_id; ?>" onkeyup="imageEdit.scaleChanged(<?php echo $post_id; ?>, 1)" onblur="imageEdit.scaleChanged(<?php echo $post_id; ?>, 1)" style="width:4em;" value="<?php echo $meta['width']; ?>" />&times;<input type="text" id="imgedit-scale-height-<?php echo $post_id; ?>" onkeyup="imageEdit.scaleChanged(<?php echo $post_id; ?>, 0)" onblur="imageEdit.scaleChanged(<?php echo $post_id; ?>, 0)" style="width:4em;" value="<?php echo $meta['height']; ?>" />
+		<span class="nowrap"><input type="text" id="imgedit-scale-width-<?php echo $post_id; ?>" onkeyup="imageEdit.scaleChanged(<?php echo $post_id; ?>, 1)" onblur="imageEdit.scaleChanged(<?php echo $post_id; ?>, 1)" style="width:4em;" value="<?php echo isset( $meta['width'] ) ? $meta['width'] : 0; ?>" />&times;<input type="text" id="imgedit-scale-height-<?php echo $post_id; ?>" onkeyup="imageEdit.scaleChanged(<?php echo $post_id; ?>, 0)" onblur="imageEdit.scaleChanged(<?php echo $post_id; ?>, 0)" style="width:4em;" value="<?php echo isset( $meta['height'] ) ? $meta['height'] : 0; ?>" />
 		<span class="imgedit-scale-warn" id="imgedit-scale-warn-<?php echo $post_id; ?>">!</span></span>
 		<input type="button" onclick="imageEdit.action(<?php echo "$post_id, '$nonce'"; ?>, 'scale')" class="button-primary" value="<?php esc_attr_e( 'Scale' ); ?>" />
 		</div>
@@ -499,7 +502,7 @@ function wp_restore_image($post_id) {
 					$delpath = apply_filters('wp_delete_file', $file);
 					@unlink($delpath);
 				}
-			} else {
+			} elseif ( isset( $meta['width'], $meta['height'] ) ) {
 				$backup_sizes["full-$suffix"] = array('width' => $meta['width'], 'height' => $meta['height'], 'file' => $parts['basename']);
 			}
 		}
diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 1d6d91a6b3..573c4db2ab 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -1127,7 +1127,7 @@ function get_media_item( $attachment_id, $args = null ) {
 
 	$media_dims = '';
 	$meta = wp_get_attachment_metadata( $post->ID );
-	if ( is_array( $meta ) && array_key_exists( 'width', $meta ) && array_key_exists( 'height', $meta ) )
+	if ( isset( $meta['width'], $meta['height'] ) )
 		$media_dims .= "<span id='media-dims-$post->ID'>{$meta['width']}&nbsp;&times;&nbsp;{$meta['height']}</span> ";
 	$media_dims = apply_filters( 'media_meta', $media_dims, $post );
 
@@ -2368,7 +2368,7 @@ function attachment_submitbox_metadata() {
 
 	$media_dims = '';
 	$meta = wp_get_attachment_metadata( $post->ID );
-	if ( is_array( $meta ) && array_key_exists( 'width', $meta ) && array_key_exists( 'height', $meta ) )
+	if ( isset( $meta['width'], $meta['height'] ) )
 		$media_dims .= "<span id='media-dims-$post->ID'>{$meta['width']}&nbsp;&times;&nbsp;{$meta['height']}</span> ";
 	$media_dims = apply_filters( 'media_meta', $media_dims, $post );
 
diff --git a/wp-includes/media.php b/wp-includes/media.php
index 9ba8e295ec..ab2cf3e334 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -164,7 +164,7 @@ function image_downsize($id, $size = 'medium') {
 			$is_intermediate = true;
 		}
 	}
-	if ( !$width && !$height && isset($meta['width'], $meta['height']) ) {
+	if ( !$width && !$height && isset( $meta['width'], $meta['height'] ) ) {
 		// any other type: use the real image
 		$width = $meta['width'];
 		$height = $meta['height'];
@@ -780,7 +780,10 @@ function gallery_shortcode($attr) {
 	foreach ( $attachments as $id => $attachment ) {
 		$link = isset($attr['link']) && 'file' == $attr['link'] ? wp_get_attachment_link($id, $size, false, false) : wp_get_attachment_link($id, $size, true, false);
 		$image_meta  = wp_get_attachment_metadata( $id );
-		$orientation = ( $image_meta['height'] > $image_meta['width'] ) ? 'portrait' : 'landscape';
+
+		$orientation = '';
+		if ( isset( $image_meta['height'], $image_meta['width'] ) )
+			$orientation = ( $image_meta['height'] > $image_meta['width'] ) ? 'portrait' : 'landscape';
 
 		$output .= "<{$itemtag} class='gallery-item'>";
 		$output .= "
@@ -1626,12 +1629,13 @@ function wp_prepare_attachment_for_js( $attachment ) {
 			}
 		}
 
-		$sizes['full'] = array(
-			'height'      => $meta['height'],
-			'width'       => $meta['width'],
-			'url'         => $attachment_url,
-			'orientation' => $meta['height'] > $meta['width'] ? 'portrait' : 'landscape',
-		);
+		$sizes['full'] = array( 'url' => $attachment_url );
+
+		if ( isset( $meta['height'], $meta['width'] ) ) {
+			$sizes['full']['height'] = $meta['height'];
+			$sizes['full']['width'] = $meta['width'];
+			$sizes['full']['orientation'] = $meta['height'] > $meta['width'] ? 'portrait' : 'landscape';
+		}
 
 		$response = array_merge( $response, array( 'sizes' => $sizes ), $sizes['full'] );
 	}
diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 8b8f42c8fc..2150b46ecd 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -1013,8 +1013,10 @@ function get_uploaded_header_images() {
 		$header_images[$header_index]['attachment_id'] =  $header->ID;
 		$header_images[$header_index]['url'] =  $url;
 		$header_images[$header_index]['thumbnail_url'] =  $url;
-		$header_images[$header_index]['width'] = $header_data['width'];
-		$header_images[$header_index]['height'] = $header_data['height'];
+		if ( isset( $header_data['width'] ) )
+			$header_images[$header_index]['width'] = $header_data['width'];
+		if ( isset( $header_data['height'] ) )
+			$header_images[$header_index]['height'] = $header_data['height'];
 	}
 
 	return $header_images;