From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Fri, 25 Nov 2022 18:23:46 +0000 (-0800)
Subject: Revert "core plugin: stop emitting an empty 'alt' tag in cmap output"
X-Git-Tag: 7.0.4~7^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a3e26c2e4cf7d2a2554337d241e5466482c92a2f;p=graphviz

Revert "core plugin: stop emitting an empty 'alt' tag in cmap output"

This reverts commit a214b9dc2be6b4a9d27196e2c43f7bf2b0ff0002. It turns out the
W3C specification for this part of HTML requires the `alt` attribute if the
`href` attribute is set. We will need to figure out an alternative of what to
set this to for accessibility.

Gitlab: closes #2319, re-opens #265
Reported-by: Albert
---

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64fccf4ab..338279d03 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased (7.0.4)]
 
+### Fixed
+
+- The `alt` attributes are once again set in the cmap output. This was a
+  regression in Graphviz 7.0.2, that intentionally removed these but did not
+  account for the W3C specification making these attributes required when the
+  `href` attribute is set. #265, #2319
+
 ## [7.0.3] – 2022-11-26
 
 ### Changed
diff --git a/plugin/core/gvrender_core_map.c b/plugin/core/gvrender_core_map.c
index a5a304e3d..3f62d4a37 100644
--- a/plugin/core/gvrender_core_map.c
+++ b/plugin/core/gvrender_core_map.c
@@ -114,6 +114,17 @@ static void map_output_shape (GVJ_t *job, map_shape_t map_shape, pointf * AF, in
 	    gvputs_xml(job, tooltip);
 	    gvputs(job, "\"");
 	}
+        /*
+	 * alt text is intended for the visually impaired, but such
+	 * folk are not likely to be clicking around on a graph anyway.
+	 * IE on the PC platform (but not on Macs) incorrectly
+	 * uses (non-empty) alt strings instead of title strings for tooltips.
+	 * To make tooltips work and avoid this IE issue,
+	 * while still satisfying usability guidelines
+	 * that require that there is always an alt string,
+	 * we generate just an empty alt string.
+	 */
+        gvputs(job, " alt=\"\"");
 
         gvputs(job, " coords=\"");
         switch (map_shape) {