[exams] Remove db error checks, add POST redirect, response code

- Error checks for DB queries are pointless; the DB functions call
  an error handler by default and do not return
- Add a redirect if any of the handlers in doPreprocess return and
  we're in a POST request as a safety measure
- Fix virtual HTTP response code when editing lecture

1 files changed, 17 insertions, 19 deletions

diff --git a/modules-available/exams/page.inc.php b/modules-available/exams/page.inc.php
index 8707c4ae..42294990 100644
--- a/modules-available/exams/page.inc.php
+++ b/modules-available/exams/page.inc.php
@@ -330,19 +330,16 @@ class Page_Exams extends Page
 
 		if ($examid === 0) {
 			// No examid given, is add
-			$res = Database::exec("INSERT INTO exams(lectureid, starttime, endtime, autologin, description) VALUES(:lectureid, :starttime, :endtime, :autologin, :description);",
-					compact('lectureid', 'starttime', 'endtime', 'autologin', 'description')) !== false;
+			Database::exec("INSERT INTO exams(lectureid, starttime, endtime, autologin, description)
+					VALUES(:lectureid, :starttime, :endtime, :autologin, :description);",
+					compact('lectureid', 'starttime', 'endtime', 'autologin', 'description'));
 
 			$exam_id = Database::lastInsertId();
 			foreach ($locationids as $lid) {
-				$res = $res && Database::exec("INSERT INTO exams_x_location(examid, locationid) VALUES(:exam_id, :lid)", compact('exam_id', 'lid')) !== false;
-			}
-			if ($res === false) {
-				Message::addError('exam-not-added');
-				Audit::overrideResponseCode(500);
-			} else {
-				Message::addInfo('exam-added-success');
+				Database::exec("INSERT INTO exams_x_location(examid, locationid)
+						VALUES(:exam_id, :lid)", compact('exam_id', 'lid'));
 			}
+			Message::addInfo('exam-added-success');
 			Util::redirect('?do=exams', 200);
 		}
 
@@ -354,21 +351,18 @@ class Page_Exams extends Page
 		}
 
 		/* update fields */
-		$res = Database::exec("UPDATE exams SET lectureid = :lectureid, starttime = :starttime, endtime = :endtime, autologin = :autologin, description = :description WHERE examid = :examid",
-				compact('lectureid', 'starttime', 'endtime', 'description', 'examid', 'autologin')) !== false;
+		Database::exec("UPDATE exams SET lectureid = :lectureid, starttime = :starttime, endtime = :endtime,
+                 autologin = :autologin, description = :description WHERE examid = :examid",
+				compact('lectureid', 'starttime', 'endtime', 'description', 'examid', 'autologin'));
 		/* drop all connections and reconnect to rooms */
-		$res = $res && Database::exec("DELETE FROM exams_x_location WHERE examid = :examid", compact('examid')) !== false;
+		Database::exec("DELETE FROM exams_x_location WHERE examid = :examid", compact('examid'));
 		/* reconnect */
 		foreach ($locationids as $lid) {
-			$res = $res && Database::exec("INSERT INTO exams_x_location(examid, locationid) VALUES(:examid, :lid)", compact('examid', 'lid')) !== false;
+			Database::exec("INSERT INTO exams_x_location(examid, locationid)
+					VALUES(:examid, :lid)", compact('examid', 'lid'));
 		}
-		if ($res !== false) {
 			Message::addInfo("changes-successfully-saved");
-		} else {
-			Message::addError("error-while-saving-changes");
-			Audit::overrideResponseCode(500);
-		}
-		Util::redirect('?do=exams');
+		Util::redirect('?do=exams', 200);
 	}
 
 	protected function doPreprocess()
@@ -454,6 +448,10 @@ class Page_Exams extends Page
 			ErrorHandler::traceError("action not implemented");
 
 		}
+		if (Request::isPost()) {
+			// Safety redirect - should not happen
+			Util::redirect('?do=exams');
+		}
 	}
 
 	private function getLocationLookupJson()