Respond to CR.

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m

@@ -249,6 +249,11 @@ NS_ASSUME_NONNULL_BEGIN
             [self.dateHeaderView autoPinTrailingToSuperviewMarginWithInset:self.conversationStyle.gutterTrailing],
             [self.dateHeaderView autoPinEdgeToSuperviewEdge:ALEdgeTop],
 
+            // DO NOT pin to the bottom of dateHeaderView.
+            //
+            // Being a UIStackView, it doesn't reflect the spacing below the date
+            // header contents.  Instead pin using dateHeaderHeight which includes
+            // the spacing.
             [self.messageBubbleView autoPinEdge:ALEdgeTop
                                          toEdge:ALEdgeTop
                                          ofView:self.dateHeaderView
@@ -365,7 +370,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (CGFloat)dateHeaderStrokeThickness
 {
-    return 1.f / UIScreen.mainScreen.scale;
+    return CGHairlineWidth();
 }
 
 - (CGFloat)dateHeaderBottomMargin

Signal/src/ViewControllers/ConversationView/Cells/OWSUnreadIndicatorCell.m

@@ -103,8 +103,10 @@ NS_ASSUME_NONNULL_BEGIN
     self.layoutConstraints = @[
         [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeTop],
         [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeBottom],
-        [self.stackView autoPinLeadingToSuperviewMarginWithInset:self.conversationStyle.fullWidthGutterLeading],
-        [self.stackView autoPinTrailingToSuperviewMarginWithInset:self.conversationStyle.fullWidthGutterTrailing],
+        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeLeading
+                                         withInset:self.conversationStyle.fullWidthGutterLeading],
+        [self.stackView autoPinEdgeToSuperviewEdge:ALEdgeTrailing
+                                         withInset:self.conversationStyle.fullWidthGutterTrailing],
     ];
 }
 
@@ -128,7 +130,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (CGFloat)strokeThickness
 {
-    return 1.f / UIScreen.mainScreen.scale;
+    return CGHairlineWidth();
 }
 
 - (CGSize)cellSizeWithTransaction:(YapDatabaseReadTransaction *)transaction

SignalMessaging/categories/UIView+OWS.h

@@ -170,4 +170,6 @@ CG_INLINE CGSize CGSizeMax(CGSize size1, CGSize size2)
     return CGSizeMake(MAX(size1.width, size2.width), MAX(size1.height, size2.height));
 }
 
+CGFloat CGHairlineWidth();
+
 NS_ASSUME_NONNULL_END

SignalMessaging/categories/UIView+OWS.m

@@ -542,4 +542,9 @@ CGFloat ScaleFromIPhone5(CGFloat iPhone5Value)
 
 @end
 
+CGFloat CGHairlineWidth()
+{
+    return 1.f / UIScreen.mainScreen.scale;
+}
+
 NS_ASSUME_NONNULL_END