Add support for <heading > in app description

docs/xml/metainfo-component.xml

@@ -247,6 +247,9 @@
 			<para>Unordered list (<literal>ul</literal>), with list items (<literal>li</literal>)</para>
 			</listitem>
 			<listitem>
+			<para>Heading (<literal>heading</literal>)</para>
+			</listitem>
+			<listitem>
 			<para>
 				Within paragraphs and list items, emphasis (<literal>em</literal>) and inline code (<literal>code</literal>) text styles are supported.
 				The emphasis is commonly rendered in italic, while inline code is shown in a monospaced font.

src/as-utils.c

@@ -259,6 +259,28 @@ as_description_markup_convert (const gchar *markup, AsMarkupKind to_kind, GError
 			} else {
 				g_string_append_printf (str, "%s\n", clean_text);
 			}
+		} else if ((g_strcmp0 ((gchar*) iter->name, "heading") == 0)) {
+			g_autofree gchar *clean_text = NULL;
+			g_autofree gchar *text_content = as_xml_get_node_value_raw (iter);
+			g_auto(GStrv) spl = NULL;
+
+			/* Apparently the element is empty, which is odd. But we better add it instead
+			 * of completely ignoring it. */
+			if (text_content == NULL)
+				text_content = g_strdup ("");
+
+			/* remove extra whitespaces and linebreaks */
+			clean_text = as_sanitize_text_spaces (text_content);
+
+			if (str->len > 0)
+				g_string_append (str, "\n");
+
+			spl = as_markup_strsplit_words (clean_text, 100);
+			if (spl != NULL) {
+				for (guint i = 0; spl[i] != NULL; i++) {
+					g_string_append_printf (str, "## %s\n", clean_text);
+				}
+			}
 		} else if ((g_strcmp0 ((gchar*) iter->name, "ul") == 0) || (g_strcmp0 ((gchar*) iter->name, "ol") == 0)) {
 			g_autofree gchar *item_c = NULL;
 			gboolean is_ordered_list = g_strcmp0 ((gchar*) iter->name, "ol") == 0;

src/as-validator.c

@@ -2091,7 +2091,7 @@ as_validator_check_release (AsValidator *validator, xmlNode *node, AsFormatStyle
 		}
 
 		/* checks if the description is put outside a description tag */
-		if (as_str_equal0 (node_name, "p") || as_str_equal0 (node_name, "ol") || as_str_equal0 (node_name, "ul") || as_str_equal0 (node_name, "li")) {
+		if (as_str_equal0 (node_name, "p") || as_str_equal0 (node_name, "ol") || as_str_equal0 (node_name, "ul") || as_str_equal0 (node_name, "li") || as_str_equal0 (node_name, "heading")) {
 			as_validator_add_issue (validator, node, "release-description-outside-tag", node_name);
 			continue;
 		}