Use configured favicon for OpenSearch entries

Previously, we were using an hardcoded image file that was not matching
the new MantisBT icon.

This references the standard MantisBT favicon instead, and allows
administrators to customize their Browser Search with their own icon.

Fixes #11964

browser_search_plugin.php

@@ -37,6 +37,7 @@
 $f_type = gpc_get_string( 'type', 'text' );
 
 $t_path = config_get_global( 'path' );
+$t_icon = $t_path . config_get_global( 'favicon_image' );
 $t_searchform = $t_path . 'view_all_bug_page.php';
 
 if( strtolower( $f_type ) == 'id' ) {
@@ -57,7 +58,7 @@
 	<ShortName><?php echo $t_shortname; ?></ShortName>
 	<Description><?php echo $t_description; ?></Description>
 	<InputEncoding>UTF-8</InputEncoding>
-	<Image width="16" height="16">data:image/png,%89PNG%0D%0A%1A%0A%00%00%00%0DIHDR%00%00%00%10%00%00%00%10%08%06%00%00%00%1F%F3%FFa%00%00%00%01sRGB%00%AE%CE%1C%E9%00%00%00%06bKGD%00%FF%00%FF%00%FF%A0%BD%A7%93%00%00%00%09pHYs%00%00%0D%12%00%00%0D%3A%01%E8%DD%99%DE%00%00%00%07tIME%07%D8%0A%1B%035%18L%0A%18d%00%00%02AIDAT8%CB%8D%93%BDOZa%18%C5%7F%7C(%97%8FF%CA%0DU%7B%5BCj%D0Z%E3%AA%12%1C%D4%85A%A2%5D%5C%1C%1C%8C%93%FF%83I%FF%13%07%12'0.%9A%90%88B%24%C6%0Ej4bJ%1A%8C%A2%40%FC%00%8C%20%22%B7p%3Bq%95R%9B%9E%E9%7D%CE%9Bs%F2%BC%E7y%5EM%A9%24%2B%3E_%9CX%2C%87%2C%D7x%0D%82%A0cb%C2A%20%90%40%10t%8C%8C%BC%C7%E3%F9%88%FE%EC%AC%402Y%F8%A7%18%C0%EBu%B0%B6v%06%40%B9%5Cec%E3%02%9DN%83%CEj%FD%FAm%7C%FC%03%FD%FD%22%C9d%81J%A5%D9%A8%BB%BB%8DJ%A5%CA%F9y%B1%81%CF%E7%CBhs%B9'%FC%FE%04%91H%8A%E9%E9n%FA%FA%DE6%19%B8%5C%1D%EC%ED%DD4%F1%B9%DC%13%DAzq%7D%FD%C8%D2%D2%0FDQ%60r%D2%81V%AB%01%C0f3%90%CF%97%A9%D5%14Uh%B7%0B%EAY%FF%A7k4%9AA%92%CC%CC%CD%F5!%CB5%06%06D%0E%0En%D0h%40Q%C0%E9lcv%F63%8B%8B%DF%01%9E%3Bx%89%AB%AB%12%ED%EDF%86%86%DA1%99%F4%B8%DD%9D%B8%DD%9Dj%98%A2(%60%B3%19%5E7%B0Z%0DH%92%A5%813%9B%F5%F4%F6Z%B1%DB%8D%00j%D8%0D%06%92d%06%E0%F6%B6%CC%E6%E6%A5%CA%17%8B2%DB%DB%19%BC%5E%07%F1%F8%1D%0F%0F2%C5%A2%DC%9C%C1%C2%C2%00%3B%3B%19%C2%E1%14~%7F%02E%81%9E%1E%2B%85B%05%87%E3%0DF%A3%1E%8B%A5%85L%A6%F4%F7%10%1F%1F%7F1%3A*1%3C%DC%C1%F1q%96x%FC%8El%B6%CC%FD%7D%85%99%99%1E%02%81%04SS%9F%08%85.TM%C3%13%C2%E1%14fs%0B%E9%F4%03%A2(0%3F%FF%85%C1%C1w%1C%1E%DE%B2%B5%95%E2%E8(K%B5Zcw%F7%EA%EF%1DD%A3%19%BA%BA%2C%B8%5C%1D%AC%AC%9C%B2%BE~%8E%C9%D4B%B5%AA%10%0A%5Db%B7%1B%D9%DF%BFiX%7Bm%7D%1Cu%2C%2F%FF%C4%E7%8B36%26%A1%D5j89%C9%A9w%8A%A2%10%89%A4%D5%DAf3%A0Y%5D%3DU%82%C1d%D3(%5B%5B%B58%9DVb%B1g%83%FA2%D5%E1%F1t%A1)%16%2BJ0xA4%9A%A6%5C%AE%F2%3Fx%F9%9D%7F%03%B4%C6%E9%B0%15%8B%D3U%00%00%00%00IEND%AEB%60%82</Image>
+	<Image width="16" height="16" type="image/x-icon"><?php echo $t_icon; ?></Image>
 	<Url type="text/html" method="GET" template="<?php echo $t_url; ?>"></Url>';
 	<moz:SearchForm><?php echo $t_searchform; ?></moz:SearchForm>
 </OpenSearchDescription>

config_defaults_inc.php

@@ -857,7 +857,9 @@
 $g_admin_checks = ON;
 
 /**
- * Favicon image
+ * Favicon image.
+ * This icon should be of 'image/x-icon' MIME type, and its size 16x16 pixels.
+ * It is also used to decorate OpenSearch Browser search entries.
  * @global string $g_favicon_image
  */
 $g_favicon_image = 'images/favicon.ico';

docbook/Admin_Guide/en-US/config/display.xml

@@ -17,7 +17,12 @@
 		<varlistentry>
 			<term>$g_favicon_image</term>
 			<listitem>
-				<para>Path to the favorites icon relative to MantisBT root folder (default 'images/favicon.ico').</para>
+				<para>Path to the favorites icon relative to MantisBT root folder
+					This icon should be of <emphasis>image/x-icon</emphasis> MIME type,
+					and its size 16x16 pixels. It is also used to decorate
+					OpenSearch Browser search entries.
+					(default 'images/favicon.ico').
+				</para>
 			</listitem>
 		</varlistentry>
 		<varlistentry>