From bfd8eb63c6ee79e58033020c9ae9524b691dbb96 Mon Sep 17 00:00:00 2001
From: Michael Kirk <michael@signal.org>
Date: Thu, 13 Sep 2018 10:07:46 -0500
Subject: [PATCH] Add some comments/nullability annotations for clarity

---
 SignalServiceKit/src/Account/TSPreKeyManager.m | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/SignalServiceKit/src/Account/TSPreKeyManager.m b/SignalServiceKit/src/Account/TSPreKeyManager.m
index 35a6ca311..43005acdd 100644
--- a/SignalServiceKit/src/Account/TSPreKeyManager.m
+++ b/SignalServiceKit/src/Account/TSPreKeyManager.m
@@ -188,13 +188,15 @@ static const NSUInteger kMaxPrekeyUpdateFailureCount = 5;
 
 + (void)clearSignedPreKeyRecords {
     OWSPrimaryStorage *primaryStorage = [OWSPrimaryStorage sharedManager];
-    NSNumber *currentSignedPrekeyId = [primaryStorage currentSignedPrekeyId];
+    NSNumber *_Nullable currentSignedPrekeyId = [primaryStorage currentSignedPrekeyId];
     [self clearSignedPreKeyRecordsWithKeyId:currentSignedPrekeyId];
 }
 
-+ (void)clearSignedPreKeyRecordsWithKeyId:(NSNumber *)keyId
++ (void)clearSignedPreKeyRecordsWithKeyId:(NSNumber *_Nullable)keyId
 {
     if (!keyId) {
+        // currentSignedPreKeyId should only be nil before we've completed registration.
+        // We have this guard here for robustness, but we should never get here.
         OWSFailDebug(@"Ignoring request to clear signed preKeys since no keyId was specified");
         return;
     }