WIP

14357.diff

diff --git a/phpBB/phpbb/textformatter/s9e/factory.php b/phpBB/phpbb/textformatter/s9e/factory.php
index 5cbf2712f..14bca2ec1 100644
--- a/phpBB/phpbb/textformatter/s9e/factory.php
+++ b/phpBB/phpbb/textformatter/s9e/factory.php
@@ -14,6 +14,7 @@
 namespace phpbb\textformatter\s9e;
 
 use s9e\TextFormatter\Configurator;
+use s9e\TextFormatter\Configurator\Helpers\TemplateHelper;
 use s9e\TextFormatter\Configurator\Items\AttributeFilters\RegexpFilter;
 use s9e\TextFormatter\Configurator\Items\UnsafeTemplate;
 
@@ -282,21 +283,11 @@ class factory implements \phpbb\textformatter\cache_interface
 		}
 
 		// Load custom BBCodes
-		foreach ($this->data_access->get_bbcodes() as $row)
+		foreach ($this->get_custom_bbcodes() as $definition => $template)
 		{
-			// Insert the board's URL before {LOCAL_URL} tokens
-			$tpl = preg_replace_callback(
-				'#\\{LOCAL_URL\\d*\\}#',
-				function ($m)
-				{
-					return generate_board_url() . '/' . $m[0];
-				},
-				$row['bbcode_tpl']
-			);
-
 			try
 			{
-				$configurator->BBCodes->addCustom($row['bbcode_match'], new UnsafeTemplate($tpl));
+				$configurator->BBCodes->addCustom($definition, new UnsafeTemplate($template));
 			}
 			catch (\Exception $e)
 			{
@@ -442,6 +433,87 @@ class factory implements \phpbb\textformatter\cache_interface
 	}
 
 	/**
+	* Return the custom BBCodes configuration
+	*
+	* @return array Associative array of [definition => template]
+	*/
+	protected function get_custom_bbcodes()
+	{
+		$definitions = array();
+		foreach ($this->data_access->get_bbcodes() as $row)
+		{
+			// Insert the board's URL before {LOCAL_URL} tokens
+			$template = preg_replace_callback(
+				'#\\{LOCAL_URL\\d*\\}#',
+				function ($m)
+				{
+					return generate_board_url() . '/' . $m[0];
+				},
+				$row['bbcode_tpl']
+			);
+
+			// Capture the BBCode name followed by an optional equal sign
+			preg_match('((\\w+)(=?))', strtolower($row['bbcode_match']), $m);
+			$definitions[$m[1]][$m[2]] = array($row['bbcode_match'], $template);
+		}
+
+		$bbcodes = array();
+		foreach ($definitions as $bbcode_name => $variants)
+		{
+			if (count($variants) === 1)
+			{
+				list($definition, $template) = end($variants);
+			}
+			else
+			{
+				// Use the definition from the variant that uses a param and replace {TOKEN} with
+				// {TOKEN;optional;useContent} because that's how duplicate definitions usually work
+				$definition = preg_replace(
+					'(=\\{\\w+)',
+					'$0;optional;useContent',
+					$variants['='][0]
+				);
+				$template = $this->generate_variant_template($bbcode_name, $variants['='][1], $variants[''][1]);
+			}
+			$bbcodes[$definition] = $template;
+		}
+
+		return $bbcodes;
+	}
+
+	/**
+	* Generate a template that accomodates both definitions of a custom BBCode
+	*
+	* phpBB 3.1 allows up to two definitions for the same BBCode if one of them has a default
+	* parameter and the other one does not, presumably to work around the lack of conditionals in
+	* templates. This method generates an XSL template that coalesce both templates and use an
+	* xsl:choose element to switch between the two.
+	*
+	* @param  string $bbcode_name   BBCode's name
+	* @param  string $with_param    Template used if the BBCode has a default parameter
+	* @param  string $without_param Template used if the BBCode does not have a default parameter
+	* @return string                XSL template
+	*/
+	protected function generate_variant_template($bbcode_name, $with_param, $without_param)
+	{
+		// We need to normalize both templates to XSL because we cannot use HTML templates inside of
+		// an XSL template
+		$with_param    = TemplateHelper::saveTemplate(TemplateHelper::loadTemplate($with_param));
+		$without_param = TemplateHelper::saveTemplate(TemplateHelper::loadTemplate($without_param));
+
+		$template = '<xsl:choose>'
+			. '<xsl:when test="@' . strtolower($bbcode_name) . '">'
+			. $with_param
+			. '</xsl:when>'
+			. '<xsl:otherwise>'
+			. $without_param
+			. '</xsl:otherwise>'
+			. '</xsl:choose>';
+
+		return $template;
+	}
+
+	/**
 	* Return the default BBCodes configuration
 	*
 	* @return array 2D array. Each element has a 'usage' key, a 'template' key, and an optional 'options' key