fix: narrow sidebar overlap and resync terminal width

Author: austinywang

Sources/BrowserWindowPortal.swift

@@ -732,8 +732,8 @@ final class WindowBrowserHostView: NSView {
             return false
         }
 
-        let regionMinX = dividerX - SidebarResizeInteraction.hitWidthPerSide
-        let regionMaxX = dividerX + SidebarResizeInteraction.hitWidthPerSide
+        let regionMinX = dividerX - SidebarResizeInteraction.sidebarSideHitWidth
+        let regionMaxX = dividerX + SidebarResizeInteraction.contentSideHitWidth
         return point.x >= regionMinX && point.x <= regionMaxX
     }
 

Sources/ContentView.swift

@@ -336,11 +336,13 @@ final class SidebarState: ObservableObject {
 }
 
 enum SidebarResizeInteraction {
-    static let handleWidth: CGFloat = 6
-    static let hitInset: CGFloat = 3
+    // Keep a generous drag target inside the sidebar itself, but make the
+    // terminal-side overlap very small so column-0 text selection still wins.
+    static let sidebarSideHitWidth: CGFloat = 6
+    static let contentSideHitWidth: CGFloat = 2
 
-    static var hitWidthPerSide: CGFloat {
-        hitInset + (handleWidth / 2)
+    static var totalHitWidth: CGFloat {
+        sidebarSideHitWidth + contentSideHitWidth
     }
 }
 
@@ -1788,8 +1790,12 @@ struct ContentView: View {
         case divider
     }
 
-    private var sidebarResizerHitWidthPerSide: CGFloat {
-        SidebarResizeInteraction.hitWidthPerSide
+    private var sidebarResizerSidebarHitWidth: CGFloat {
+        SidebarResizeInteraction.sidebarSideHitWidth
+    }
+
+    private var sidebarResizerContentHitWidth: CGFloat {
+        SidebarResizeInteraction.contentSideHitWidth
     }
 
     private func maxSidebarWidth(availableWidth: CGFloat? = nil) -> CGFloat {
@@ -1865,8 +1871,8 @@ struct ContentView: View {
 
     private func dividerBandContains(pointInContent point: NSPoint, contentBounds: NSRect) -> Bool {
         guard point.y >= contentBounds.minY, point.y <= contentBounds.maxY else { return false }
-        let minX = sidebarWidth - sidebarResizerHitWidthPerSide
-        let maxX = sidebarWidth + sidebarResizerHitWidthPerSide
+        let minX = sidebarWidth - sidebarResizerSidebarHitWidth
+        let maxX = sidebarWidth + sidebarResizerContentHitWidth
         return point.x >= minX && point.x <= maxX
     }
 
@@ -2046,7 +2052,7 @@ struct ContentView: View {
         GeometryReader { proxy in
             let totalWidth = max(0, proxy.size.width)
             let dividerX = min(max(sidebarWidth, 0), totalWidth)
-            let leadingWidth = max(0, dividerX - sidebarResizerHitWidthPerSide)
+            let leadingWidth = max(0, dividerX - sidebarResizerSidebarHitWidth)
 
             HStack(spacing: 0) {
                 Color.clear
@@ -2055,7 +2061,7 @@ struct ContentView: View {
 
                 sidebarResizerHandleOverlay(
                     .divider,
-                    width: sidebarResizerHitWidthPerSide * 2,
+                    width: SidebarResizeInteraction.totalHitWidth,
                     availableWidth: totalWidth,
                     accessibilityIdentifier: "SidebarResizer"
                 )

Sources/GhosttyTerminalView.swift

@@ -7005,6 +7005,16 @@ final class GhosttySurfaceScrollView: NSView {
             self?.synchronizeScrollView()
         })
 
+        observers.append(NotificationCenter.default.addObserver(
+            forName: NSScroller.preferredScrollerStyleDidChangeNotification,
+            object: nil,
+            // Match AppKit's geometry change immediately so the terminal width
+            // does not stay stuck behind a legacy scrollbar gutter.
+            queue: nil
+        ) { [weak self] _ in
+            self?.handlePreferredScrollerStyleChange()
+        })
+
     }
 
     required init?(coder: NSCoder) {
@@ -9040,6 +9050,21 @@ final class GhosttySurfaceScrollView: NSView {
         synchronizeScrollView()
     }
 
+    private func handlePreferredScrollerStyleChange() {
+        guard Thread.isMainThread else {
+            DispatchQueue.main.async { [weak self] in
+                self?.handlePreferredScrollerStyleChange()
+            }
+            return
+        }
+
+        // Retile just the scroll view so contentSize reflects the current
+        // scrollbar mode without perturbing viewport origin or hosted view
+        // geometry; the broader reconcile path caused visible content glitches.
+        scrollView.tile()
+        _ = synchronizeCoreSurface()
+    }
+
     private func documentHeight() -> CGFloat {
         let contentHeight = scrollView.contentSize.height
         let cellHeight = surfaceView.cellSize.height

Sources/Panels/BrowserPanelView.swift

@@ -5270,7 +5270,7 @@ struct WebViewRepresentable: NSViewRepresentable {
             // Pass through a narrow leading-edge band so the shared sidebar divider
             // handle can receive hover/click even when WKWebView is attached here.
             // Keeping this deterministic avoids flicker from dynamic left-edge scans.
-            guard point.x >= 0, point.x <= SidebarResizeInteraction.hitWidthPerSide else {
+            guard point.x >= 0, point.x <= SidebarResizeInteraction.contentSideHitWidth else {
                 return false
             }
             guard let window, let contentView = window.contentView else {

Sources/TerminalWindowPortal.swift

@@ -243,8 +243,8 @@ final class WindowTerminalHostView: NSView {
             return false
         }
 
-        let regionMinX = dividerX - SidebarResizeInteraction.hitWidthPerSide
-        let regionMaxX = dividerX + SidebarResizeInteraction.hitWidthPerSide
+        let regionMinX = dividerX - SidebarResizeInteraction.sidebarSideHitWidth
+        let regionMaxX = dividerX + SidebarResizeInteraction.contentSideHitWidth
         return point.x >= regionMinX && point.x <= regionMaxX
     }