apply last character font size to the attachment

ElementX/Sources/Other/Pills/MessageText.swift

@@ -102,14 +102,34 @@ struct MessageText: UIViewRepresentable {
                                        size: CGSize(width: trailingReservedSize.width,
                                                     height: max(trailingReservedSize.height, 1)))
 
+            // Inherit the font from the preceding character so the appended runs
+            // (newline and attachment) carry the same line metrics as the surrounding
+            // text — otherwise a small default font on those characters can shrink the
+            // line height and clip e.g. a font-boosted lone emoji.
+            let trailingFont = baseText.length > 0
+                ? baseText.attribute(.font, at: baseText.length - 1, effectiveRange: nil)
+                : nil
+
             // When the last paragraph's natural text direction doesn't match the layout
             // direction, the inline attachment would land on the wrong side and overlap the
             // overlaid timestamp. Force it onto its own line so the bubble just grows taller.
             if !lastParagraphDirectionMatchesLayout(in: combined) {
-                combined.append(NSAttributedString(string: "\n"))
+                let newlineString = NSMutableAttributedString(string: "\n")
+                if let trailingFont {
+                    newlineString.addAttribute(.font,
+                                               value: trailingFont,
+                                               range: NSRange(location: 0, length: newlineString.length))
+                }
+                combined.append(newlineString)
             }
 
-            combined.append(NSAttributedString(attachment: attachment))
+            let attachmentString = NSMutableAttributedString(attachment: attachment)
+            if let trailingFont {
+                attachmentString.addAttribute(.font,
+                                              value: trailingFont,
+                                              range: NSRange(location: 0, length: attachmentString.length))
+            }
+            combined.append(attachmentString)
         }
 
         return combined

ElementX/Sources/Screens/Timeline/View/Style/TimelineStyler.swift

@@ -152,6 +152,15 @@ struct TimelineItemStyler_Previews: PreviewProvider, TestablePreview {
                                                                  canBeRepliedTo: true,
                                                                  sender: .test,
                                                                  content: .init(body: "באמת! -- house!"))
+    
+    static let bigEmoji = TextRoomTimelineItem(id: .randomEvent,
+                                               timestamp: .mock,
+                                               isOutgoing: true,
+                                               isEditable: false,
+                                               canBeRepliedTo: true,
+                                               shouldBoost: true,
+                                               sender: .test,
+                                               content: .init(body: "😮"))
 
     static var testView: some View {
         VStack(spacing: 0) {
@@ -172,6 +181,7 @@ struct TimelineItemStyler_Previews: PreviewProvider, TestablePreview {
             TextRoomTimelineView(timelineItem: rtlStringThatContainsLtr)
             TextRoomTimelineView(timelineItem: ltrStringThatFinishesInRtl)
             TextRoomTimelineView(timelineItem: rtlStringThatFinishesInLtr)
+            TextRoomTimelineView(timelineItem: bigEmoji)
         }
     }
 

ElementX/Sources/Screens/Timeline/View/TimelineItemViews/FormattedBodyText.swift

@@ -24,7 +24,7 @@ struct FormattedBodyText: View {
     private var attributedComponents: [AttributedStringBuilderComponent] {
         var adjustedAttributedString = attributedString
         
-        // Required to allow the underlying TextView to use  body font when no font is specifie in the AttributedString.
+        // Required to allow the underlying TextView to use  body font when no font is specified in the AttributedString.
         adjustedAttributedString.mergeAttributes(defaultAttributesContainer, mergePolicy: .keepCurrent)
         
         let string = String(attributedString.characters)