From 50952b3243cbc4585b2e3f6f609445d34bc4d794 Mon Sep 17 00:00:00 2001
From: Aidan Woods <aidantwoods@gmail.com>
Date: Sun, 2 Oct 2016 18:26:13 +0100
Subject: [PATCH] Line handler may prevent specified element nesting

This commit serves to add comments detailing parts of the new functionality, and to adjust syntax preferences to match that of the surrounding document. The commit title also now reflects the most significant change made.
---
 Parsedown.php | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/Parsedown.php b/Parsedown.php
index b708236..6b6df9c 100644
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -1003,22 +1003,19 @@ class Parsedown
 
             foreach ($this->InlineTypes[$marker] as $inlineType)
             {
+                # check to see if the current inline type is nestable in the current context
+
                 foreach ($non_nestables as $key => $non_nestable)
                 {
-                    if (is_array($non_nestable))
+                    # case that we used array syntax 
+                    if (is_array($non_nestable) and $non_nestable[0] === $inlineType)
                     {
-                        
-                        if ($non_nestable[0] === $inlineType)
-                        {
-                            continue 2;
-                        }
+                        continue 2;
                     }
-                    else
+                    # case that we used plain string syntax
+                    elseif ( ! is_array($non_nestable) and $non_nestable === $inlineType)
                     {
-                        if ($non_nestable === $inlineType)
-                        {
-                            continue 2;
-                        }
+                        continue 2;
                     }
                 }
 
@@ -1043,25 +1040,27 @@ class Parsedown
                     $Inline['position'] = $markerPosition;
                 }
 
+                # cause the new element to 'inherit' our non nestables, if appropriate
+
                 foreach ($non_nestables as $key => $non_nestable)
                 {
-                    if (is_array($non_nestable) && isset($non_nestable[1]) && is_int($non_nestable[1])){
-                        if($non_nestable[1] > 1)
-                        {
-                            $Inline['element']['non_nestables'][] = array($non_nestable[0], $non_nestable[1] -1);
-                        }
-                        
+                    # array syntax, and depth is sufficient to pass on
+                    if (is_array($non_nestable) and isset($non_nestable[1]) and
+                        is_int($non_nestable[1]) and $non_nestable[1] > 1)
+                    {
+                        $Inline['element']['non_nestables'][] = array($non_nestable[0], $non_nestable[1] -1);
                     }
-                    elseif (is_array($non_nestable) && ! isset($non_nestable[1]))
+                    # array syntax, and depth is indefinite
+                    elseif (is_array($non_nestable) and ! isset($non_nestable[1]))
                     {
                          $Inline['element']['non_nestables'][] = array($non_nestable[0]);
                     }
+                    # string syntax, so depth is indefinite
                     elseif ( ! is_array($non_nestable))
                     {
                         $Inline['element']['non_nestables'][] = $non_nestable;
                     }
                 }
-                
 
                 # the text that comes before the inline
                 $unmarkedText = substr($text, 0, $Inline['position']);
@@ -1450,7 +1449,10 @@ class Parsedown
         {
             $markup .= '>';
 
-            if(!isset($Element['non_nestables'])) $Element['non_nestables'] = array();
+            if (!isset($Element['non_nestables'])) 
+            {
+                $Element['non_nestables'] = array();
+            }
 
             if (isset($Element['handler']))
             {