Fix some libphutil Calendar document bugs

Summary:
Ref T10747.

  - Default to UTC if a datetime has no explicit timezone.
  - Fix a bug with escape detection that could incorrectly trigger for escaped commas.
  - Remove some unused properties (now properites of the RRULE itself).

Test Plan: See next diff.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10747

Differential Revision: https://secure.phabricator.com/D16698

Author: epriestley

src/parser/calendar/data/PhutilCalendarDateTime.php

@@ -48,7 +48,7 @@ public function getISO8601() {
 
   public function newAbsoluteDateTime() {
     $epoch = $this->getEpoch();
-    $timezone = $this->getTimezone();
+    $timezone = nonempty($this->getTimezone(), 'UTC');
     return PhutilCalendarAbsoluteDateTime::newFromEpoch($epoch, $timezone)
       ->setIsAllDay($this->getIsAllDay())
       ->setViewerTimezone($this->getViewerTimezone());

src/parser/calendar/data/PhutilCalendarEventNode.php

@@ -139,24 +139,6 @@ public function getRecurrenceRule() {
     return $this->recurrenceRule;
   }
 
-  public function setRecurrenceUntilDateTime(PhutilCalendarDateTime $date) {
-    $this->recurrenceUntilDateTime = $date;
-    return $this;
-  }
-
-  public function getRecurrenceUntilDateTime() {
-    return $this->recurrenceUntilDateTime;
-  }
-
-  public function setRecurrenceCount($recurrence_count) {
-    $this->recurrenceCount = $recurrence_count;
-    return $this;
-  }
-
-  public function getRecurrenceCount() {
-    return $this->recurrenceCount;
-  }
-
   public function setRecurrenceExceptions(array $recurrence_exceptions) {
     assert_instances_of($recurrence_exceptions, 'PhutilCalendarDateTime');
     $this->recurrenceExceptions = $recurrence_exceptions;

src/parser/calendar/ics/PhutilICSParser.php

@@ -572,6 +572,7 @@ private function unescapeTextValue($data) {
             $buf .= $c;
             break;
         }
+        $esc = false;
       }
     }