From 8023f34a6a3f87b760040be7e2cc770066bfbdde Mon Sep 17 00:00:00 2001
From: Joe Dolson <joedolson@git.wordpress.org>
Date: Wed, 27 Jan 2021 21:52:10 +0000
Subject: [PATCH] Revisions: Generate correct number of columns in
 wp_text_diff.

The function `wp_text_diff` generated an invalid table structure if the $args parameter contained any values. This patch corrects the structure generated by `wp_text_diff` and related usages so that the column count matches the data generated. Additionally, this patch passes arguments to the Revisions screen so that the screen has column headings that reflect the content in each column. Improves the accessibility and usability of the Revisions table.

Props joedolson, mehulkaklotar, afercia, adamsilverstein, zodiac1978, jeremyfelt
Fixes #25473

git-svn-id: https://develop.svn.wordpress.org/trunk@50034 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/includes/revision.php            |  2 ++
 .../class-wp-text-diff-renderer-table.php     |  8 ++---
 src/wp-includes/pluggable.php                 | 29 +++++++++++--------
 3 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/src/wp-admin/includes/revision.php b/src/wp-admin/includes/revision.php
index e5f480d0ed..496282529c 100644
--- a/src/wp-admin/includes/revision.php
+++ b/src/wp-admin/includes/revision.php
@@ -86,6 +86,8 @@ function wp_get_revision_ui_diff( $post, $compare_from, $compare_to ) {
 
 		$args = array(
 			'show_split_view' => true,
+			'title_left'      => __( 'Removed' ),
+			'title_right'     => __( 'Added' ),
 		);
 
 		/**
diff --git a/src/wp-includes/class-wp-text-diff-renderer-table.php b/src/wp-includes/class-wp-text-diff-renderer-table.php
index c55add4885..3db5a51d85 100644
--- a/src/wp-includes/class-wp-text-diff-renderer-table.php
+++ b/src/wp-includes/class-wp-text-diff-renderer-table.php
@@ -176,7 +176,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 			}
 
 			if ( $this->_show_split_view ) {
-				$r .= '<tr>' . $this->emptyLine() . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
+				$r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
 			} else {
 				$r .= '<tr>' . $this->addedLine( $line ) . "</tr>\n";
 			}
@@ -201,7 +201,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 				$line = apply_filters( 'process_text_diff_html', $processed_line, $line, 'deleted' );
 			}
 			if ( $this->_show_split_view ) {
-				$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . $this->emptyLine() . "</tr>\n";
+				$r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
 			} else {
 				$r .= '<tr>' . $this->deletedLine( $line ) . "</tr>\n";
 			}
@@ -226,7 +226,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 				$line = apply_filters( 'process_text_diff_html', $processed_line, $line, 'unchanged' );
 			}
 			if ( $this->_show_split_view ) {
-				$r .= '<tr>' . $this->contextLine( $line ) . $this->emptyLine() . $this->contextLine( $line ) . "</tr>\n";
+				$r .= '<tr>' . $this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\n";
 			} else {
 				$r .= '<tr>' . $this->contextLine( $line ) . "</tr>\n";
 			}
@@ -319,7 +319,7 @@ class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
 				$r .= $this->_deleted( array( $orig_line ), false );
 			} else { // A true changed row.
 				if ( $this->_show_split_view ) {
-					$r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->emptyLine() . $this->addedLine( $final_line ) . "</tr>\n";
+					$r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\n";
 				} else {
 					$r .= '<tr>' . $this->deletedLine( $orig_line ) . '</tr><tr>' . $this->addedLine( $final_line ) . "</tr>\n";
 				}
diff --git a/src/wp-includes/pluggable.php b/src/wp-includes/pluggable.php
index 7dee482170..c53a723fc4 100644
--- a/src/wp-includes/pluggable.php
+++ b/src/wp-includes/pluggable.php
@@ -2838,27 +2838,32 @@ if ( ! function_exists( 'wp_text_diff' ) ) :
 			return '';
 		}
 
-		$r = "<table class='diff'>\n";
+		$is_split_view       = ! empty( $args['show_split_view'] );
+		$is_split_view_class = $is_split_view ? ' is-split-view' : '';
 
-		if ( ! empty( $args['show_split_view'] ) ) {
-			$r .= "<col class='content diffsplit left' /><col class='content diffsplit middle' /><col class='content diffsplit right' />";
-		} else {
-			$r .= "<col class='content' />";
+		$r = "<table class='diff$is_split_view_class'>\n";
+
+		if ( $args['title'] ) {
+			$r .= "<caption class='diff-title'>$args[title]</caption>\n";
 		}
 
-		if ( $args['title'] || $args['title_left'] || $args['title_right'] ) {
+		if ( $args['title_left'] || $args['title_right'] ) {
 			$r .= '<thead>';
 		}
-		if ( $args['title'] ) {
-			$r .= "<tr class='diff-title'><th colspan='4'>$args[title]</th></tr>\n";
-		}
+
 		if ( $args['title_left'] || $args['title_right'] ) {
+			$th_or_td_left  = empty( $args['title_left'] ) ? 'td' : 'th';
+			$th_or_td_right = empty( $args['title_right'] ) ? 'td' : 'th';
+
 			$r .= "<tr class='diff-sub-title'>\n";
-			$r .= "\t<td></td><th>$args[title_left]</th>\n";
-			$r .= "\t<td></td><th>$args[title_right]</th>\n";
+			$r .= "\t<$th_or_td_left>$args[title_left]</$th_or_td_left>\n";
+			if ( $is_split_view ) {
+				$r .= "\t<$th_or_td_right>$args[title_right]</$th_or_td_right>\n";
+			}
 			$r .= "</tr>\n";
 		}
-		if ( $args['title'] || $args['title_left'] || $args['title_right'] ) {
+
+		if ( $args['title_left'] || $args['title_right'] ) {
 			$r .= "</thead>\n";
 		}