add function to exclude embedded images when checking message length

diff --git a/include/items.php b/include/items.php
index cf903ac13927e0399c18f36aa999d75c7159c495..2cd0e610797ca54d1a4e794e251311e90fcd01aa 100755 (executable)
--- a/include/items.php
+++ b/include/items.php
@@ -278,7 +278,116 @@ function construct_activity_target($item) {
        }
 
        return '';
-} 
+}
+
+/* limit_body_size()
+ *
+ *             The purpose of this function is to apply system message length limits to
+ *             imported messages without including any embedded photos in the length
+ *
+ *             How it works (other than when the body length is less than the max length at the outset):
+ *                     1. When the text length without embedded images is less than the max length
+ *                             a. The while() loop does run, since there are embedded images
+ *                             b. 
+ *
+ *                     2. When the text length exceeds the max length before the first embedded image
+ *
+ *                     3. When the text length exceeds the max length in between embedded images
+ *
+ *                     4. When the text length exceeds the max length after the last embedded image
+ *
+ *                     5. When there are no embedded images
+ */
+if(! function_exists('limit_body_size')) {
+function limit_body_size($body) {
+
+       logger('limit_body_size: start', LOGGER_DEBUG);
+
+       $maxlen = get_max_import_size();
+
+       // If the length of the body, including the embedded images, is smaller
+       // than the maximum, then don't waste processing looking for the images
+       if($maxlen && (strlen($body) > $maxlen)) {
+
+               logger('limit_body_size: the body length exceeds the limit', LOGGER_DEBUG);
+
+               $img_pos = array();
+               $max_pos = 0;
+
+               $body_left = $body;
+               $cnt = 0;
+               $img_pos[$cnt] = array('start' => strpos($body_left, '[img]data:'));
+               while($img_pos[$cnt]['start'] !== false) {
+
+                       // We're assuming that at this point, every opening '[img]data:' tag has a closing [/img] tag
+                       $img_pos[$cnt]['end'] = strpos(substr($body_left, $img_pos[$cnt]['start'], strlen($body_left) - $img_pos[$cnt]['start']), '[/img]');
+                       $img_pos[$cnt]['end'] += strlen('[/img]');
+                       $img_pos[$cnt]['end'] += $img_pos[$cnt]['start'];
+
+                       if(! $cnt) {
+                               // This code should only run in the first loop
+                               $textlen = $img_pos[$cnt]['start'];
+                               if( ($maxlen - $textlen) <= 0 ) {
+                                       $maxpos = $maxlen;
+                                       $maxcnt = $cnt;
+                               }
+                       }
+                       else {
+                               $newlen = $img_pos[$cnt]['start'] - $img_pos[$cnt - 1]['end'];  // The length between the last embedded image and the next
+                               if( (! $max_pos) && (($maxlen - ($textlen + $newlen)) <= 0) ) {
+                                       // $max_pos should be 0 until the message text exceeds the limit.
+                                       // If the limit has already been set, don't set it again
+                                       $len_left = $maxlen - $textlen;
+                                       $maxpos = $img_pos[$cnt - 1]['end'] + $len_left;  // We'll cut off the text at this position
+                                       $maxcnt = $cnt;
+                               }
+
+                               $textlen += $newlen;
+                       }
+
+                       $body_left = substr($body_left, $img_pos[$cnt]['end'], strlen($body_left) - $img_pos[$cnt]['end']);
+                       $cnt++;
+                       $img_pos[$cnt] = array('start' => strpos($body_left, '[img]data:') + $img_pos[$cnt - 1]['end']);
+               }
+
+               logger('limit_body_size: the while loop ran ' . $cnt . ' times', LOGGER_DEBUG);
+
+               if(! $cnt) {
+                       // The while() loop never ran -- there are no embedded images
+                       $maxpos = $maxlen;
+                       $maxcnt = $cnt;
+                       $textlen = strlen($body);
+               }
+               else {
+                       // The while() loop did run. But the end of the last embedded image may not be the end of the body
+                       // Check if the maximum length occurs between the end of the last embedded image and the end of the text
+                       $newlen = strlen($body_left);
+                       if( (! $max_pos) && (($maxlen - ($textlen + $newlen)) <= 0) ) {
+                               $len_left = $maxlen - $textlen;
+                               $maxpos = $img_pos[$cnt - 1]['end'] + $len_left;  // We'll cut off the text at this position
+                               $maxcnt = $cnt;
+                       }
+                       $textlen += $newlen;
+               }
+
+
+               if($textlen > $maxlen) {
+                       $newbody = substr($body, 0, $maxpos);  // Note: $maxpos is the position of the character AFTER the maximum length
+
+                       // Now pile all the remaining embedded images onto the end
+                       for($i = $maxcnt; $i < $cnt; $i++)
+                               $newbody = $newbody . substr($body, $img_pos[$i]['start'], $img_pos[$i]['end'] - $img_pos[$i]['start']);
+
+                       logger('limit_body_size: the text length (w/o embedded images) was ' . $textlen . ' and the limit was ' . $maxlen . '. Body truncated', LOGGER_DEBUG);
+
+                       return $newbody;
+               }
+               else // When embedded images are excluded, the text length is less than the maximum, so we're good
+                       return $body;
+       }
+       else
+               return $body;
+}}
 
 
 
@@ -414,9 +523,8 @@ function get_atom_elements($feed,$item) {
                $res['body'] = notags(base64url_decode($res['body']));
        }
 
-       $maxlen = get_max_import_size();
-       if($maxlen && (strlen($res['body']) > $maxlen))
-               $res['body'] = substr($res['body'],0, $maxlen);
+       
+       $res['body'] = limit_body_size($res['body']);
 
        // It isn't certain at this point whether our content is plaintext or html and we'd be foolish to trust 
        // the content type. Our own network only emits text normally, though it might have been converted to