fix(tmux): TmuxSessionManager critical bugs (#3, #4, #14, #24)

Geistty/GeisttyTests/TmuxSessionManagerTests.swift

@@ -3796,6 +3796,50 @@ extension TmuxSessionManagerTests {
         XCTAssertTrue(cmd.contains("11\n"),
                       "resize-pane should target 11 rows (23 * 0.5), got: \(cmd)")
     }
+
+    /// syncSplitRatioToTmux should correctly find and resize the RIGHT child pane.
+    /// This validates finding #14: the old code only checked split.left.leftmostPaneId,
+    /// which would miss panes that are the right child of a split.
+    @MainActor
+    func testSyncSplitRatioRightChildPaneSendsResizePane() {
+        let (mgr, log) = managerWithCommandLog()
+        let mock = MockTmuxSurface()
+        let layout = horizontalSplitLayout(paneA: 0, paneB: 1, totalCols: 80, rows: 24)
+        mock.stubbedWindows = [TmuxWindowInfo(id: 0, width: 80, height: 24, name: "bash")]
+        mock.stubbedWindowLayouts = [layout]
+        mock.stubbedActiveWindowId = 0
+        mock.stubbedPaneIds = [0, 1]
+        #if DEBUG
+        mgr.tmuxQuerySurfaceOverride = mock
+        #endif
+
+        mgr.controlModeActivated()
+        mgr.viewerBecameReady()
+        mgr.configureSurfaceManagement(
+            factory: { _ in nil },
+            inputHandler: { _, _ in },
+            resizeHandler: { _, _ in }
+        )
+        mgr.handleTmuxStateChanged(windowCount: 1, paneCount: 2)
+
+        // Set lastRefreshSize AFTER controlModeActivated (which resets it to nil)
+        #if DEBUG
+        mgr.setLastRefreshSizeForTesting(cols: 80, rows: 24)
+        #endif
+
+        log.commands.removeAll()
+        // Resize pane 1 (the RIGHT child) — this was broken before finding #14 fix
+        mgr.syncSplitRatioToTmux(forPaneId: 1, ratio: 0.6)
+
+        // Should send a resize-pane -x command targeting pane 1
+        XCTAssertEqual(log.commands.count, 1, "Exactly one resize command should be sent for right-child pane")
+        let cmd = log.commands.first ?? ""
+        XCTAssertTrue(cmd.hasPrefix("resize-pane -t %1 -x "),
+                      "Command should target pane 1 with -x flag, got: \(cmd)")
+        // Expected: available = 80 - 1 (divider) = 79, new size = max(1, Int(79 * 0.6)) = 47
+        XCTAssertTrue(cmd.contains("47\n"),
+                      "resize-pane should target 47 columns (79 * 0.6), got: \(cmd)")
+    }
 }
 
 // MARK: - Pending Input Display Tests
@@ -4042,8 +4086,8 @@ extension TmuxSessionManagerTests {
         // Set clipboard content
         UIPasteboard.general.string = "clipboard text"
 
-        // Set focused pane
-        mgr.setFocusedPane("5")
+        // Set focused pane (with % prefix, as in production)
+        mgr.setFocusedPane("%5")
 
         mgr.pasteTmuxBuffer()
 
@@ -4096,7 +4140,7 @@ extension TmuxSessionManagerTests {
         defer { UIPasteboard.general.string = savedClipboard }
 
         UIPasteboard.general.string = "line with \\backslash and \"quotes\""
-        mgr.setFocusedPane("0")
+        mgr.setFocusedPane("%0")
 
         mgr.pasteTmuxBuffer()
 
@@ -4121,7 +4165,7 @@ extension TmuxSessionManagerTests {
         defer { UIPasteboard.general.string = savedClipboard }
 
         UIPasteboard.general.string = "line1\nline2\rline3"
-        mgr.setFocusedPane("0")
+        mgr.setFocusedPane("%0")
 
         mgr.pasteTmuxBuffer()
 
@@ -4134,6 +4178,35 @@ extension TmuxSessionManagerTests {
                        "Raw newlines must not appear in command: got \(cmd)")
     }
 
+    /// Dollar signs and backticks must be escaped as defense-in-depth
+    /// against potential expansion when passed to set-buffer.
+    @MainActor
+    func testPasteTmuxBufferEscapesDollarAndBacktick() {
+        let mgr = TmuxSessionManager()
+        let mock = MockTmuxSurface()
+        #if DEBUG
+        mgr.tmuxQuerySurfaceOverride = mock
+        #endif
+
+        let savedClipboard = UIPasteboard.general.string
+        defer { UIPasteboard.general.string = savedClipboard }
+
+        UIPasteboard.general.string = "price is $100 and `command`"
+        mgr.setFocusedPane("%0")
+
+        mgr.pasteTmuxBuffer()
+
+        let cmd = mock.sendTmuxCommandCalls.first ?? ""
+        XCTAssertTrue(cmd.contains("\\$100"),
+                      "Dollar signs should be escaped: got \(cmd)")
+        XCTAssertTrue(cmd.contains("\\`command\\`"),
+                      "Backticks should be escaped: got \(cmd)")
+        let unescapedDollarRange = cmd.range(of: #"(?<!\\)\$"#,
+                                             options: .regularExpression)
+        XCTAssertNil(unescapedDollarRange,
+                     "Unescaped dollar sign must not appear: got \(cmd)")
+    }
+
     /// pasteTmuxBuffer should bail out when no pane is focused.
     @MainActor
     func testPasteTmuxBufferNoFocusedPaneDoesNothing() {
@@ -4170,7 +4243,7 @@ extension TmuxSessionManagerTests {
         defer { UIPasteboard.general.string = savedClipboard }
 
         UIPasteboard.general.string = "something"
-        mgr.setFocusedPane("0")
+        mgr.setFocusedPane("%0")
         mgr.pasteTmuxBuffer()
 
         // Simulate error on set-buffer
@@ -4873,6 +4946,46 @@ extension TmuxSessionManagerTests {
         mgr.handleFocusedPaneChanged(windowId: UInt32.max, paneId: UInt32.max)
     }
 
+    /// When the window matches focusedWindowId, handleFocusedPaneChanged
+    /// should update focusedPaneId via setFocusedPane.
+    @MainActor
+    func testHandleFocusedPaneChangedUpdatesFocusForMatchingWindow() {
+        let mgr = TmuxSessionManager()
+        let mock = MockTmuxSurface()
+        #if DEBUG
+        mgr.tmuxQuerySurfaceOverride = mock
+        #endif
+
+        // Set focusedWindowId to "@1" so the handler recognizes window 1
+        mgr.setFocusedWindowIdForTesting("@1")
+        mgr.setFocusedPane("%0") // initial focus
+
+        // Trigger pane change for matching window
+        mgr.handleFocusedPaneChanged(windowId: 1, paneId: 5)
+        XCTAssertEqual(mgr.focusedPaneId, "%5",
+                       "focusedPaneId should be updated to %5 for matching window")
+    }
+
+    /// When the window does NOT match focusedWindowId, handleFocusedPaneChanged
+    /// should leave focusedPaneId unchanged.
+    @MainActor
+    func testHandleFocusedPaneChangedIgnoresNonMatchingWindow() {
+        let mgr = TmuxSessionManager()
+        let mock = MockTmuxSurface()
+        #if DEBUG
+        mgr.tmuxQuerySurfaceOverride = mock
+        #endif
+
+        // Set focusedWindowId to "@1"
+        mgr.setFocusedWindowIdForTesting("@1")
+        mgr.setFocusedPane("%0") // initial focus
+
+        // Trigger pane change for a different window
+        mgr.handleFocusedPaneChanged(windowId: 2, paneId: 9)
+        XCTAssertEqual(mgr.focusedPaneId, "%0",
+                       "focusedPaneId should remain %0 for non-matching window")
+    }
+
     @MainActor
     func testHandleSubscriptionChangedDoesNotCrash() {
         let mgr = TmuxSessionManager()

Geistty/Sources/SSH/TmuxSessionManager.swift

@@ -143,6 +143,11 @@ class TmuxSessionManager: ObservableObject {
 
     // ARCHIVED: Session 127 — needsReattach + needsReattachForTesting removed
     // (destroy-and-recreate approach). See docs/archive/REATTACH_PRESERVED_SURFACES_FEB_2026.swift
+
+    /// Test-only: set focusedWindowId to test window-matching logic
+    func setFocusedWindowIdForTesting(_ windowId: String) {
+        focusedWindowId = windowId
+    }
     #endif
 
     /// Cell size from the primary surface (for calculating terminal dimensions)
@@ -1470,10 +1475,17 @@ class TmuxSessionManager: ObservableObject {
     ) -> (direction: TmuxSplitTree.Direction, ratio: Double, totalSize: Int)? {
         guard case .split(let split) = node else { return nil }
 
-        if split.left.leftmostPaneId == paneId {
-            // Found the split - calculate total size based on direction
-            let totalSize = split.direction == .horizontal ? totalCols : totalRows
-            return (split.direction, split.ratio, totalSize)
+        // Check if the target pane is a direct child of this split (on either side).
+        // The old code only checked split.left.leftmostPaneId, which missed panes
+        // that are a right child or not the leftmost leaf in a subtree.
+        if split.left.contains(paneId: paneId) || split.right.contains(paneId: paneId) {
+            // Verify that the pane is an immediate child (leaf), not deeper in a subtree.
+            // If it's deeper, we need to recurse to find the innermost containing split.
+            let isDirectChild = split.left.isPane(paneId) || split.right.isPane(paneId)
+            if isDirectChild {
+                let totalSize = split.direction == .horizontal ? totalCols : totalRows
+                return (split.direction, split.ratio, totalSize)
+            }
         }
 
         // Recurse into children with adjusted sizes
@@ -1610,9 +1622,16 @@ class TmuxSessionManager: ObservableObject {
 
     /// Handle a tmux `%window-pane-changed` notification from the Zig viewer.
     /// Fired when the focused pane within a window changes (e.g., via select-pane).
-    /// Currently log-only; future work may update pane focus indicators.
+    /// If the window matches our focused window, update input routing to the new pane
+    /// so that keystrokes are sent to the correct pane via send-keys.
     func handleFocusedPaneChanged(windowId: UInt32, paneId: UInt32) {
         logger.info("tmux focused pane changed: @\(windowId) %\(paneId)")
+
+        // Only update focus if this is our currently focused window.
+        // focusedWindowId has "@" prefix (e.g. "@0"), so format windowId to match.
+        if "@\(windowId)" == focusedWindowId {
+            setFocusedPane("%\(paneId)")
+        }
     }
 
     /// Handle a tmux `%subscription-changed` notification from the Zig viewer.
@@ -1682,9 +1701,13 @@ class TmuxSessionManager: ObservableObject {
         // - Newlines and carriage returns must be escaped to prevent breaking
         //   the tmux control-mode command framing (one command per line)
         // - Use -- to prevent content starting with - from being parsed as flags
+        // Also escape $ and backtick as defense-in-depth against potential
+        // expansion in edge cases when the content is passed to set-buffer.
         let escaped = clipboardContent
             .replacingOccurrences(of: "\\", with: "\\\\")
             .replacingOccurrences(of: "\"", with: "\\\"")
+            .replacingOccurrences(of: "$", with: "\\$")
+            .replacingOccurrences(of: "`", with: "\\`")
             .replacingOccurrences(of: "\n", with: "\\n")
             .replacingOccurrences(of: "\r", with: "\\r")
 
@@ -1698,9 +1721,10 @@ class TmuxSessionManager: ObservableObject {
                 logger.warning("set-buffer failed: \(content)")
                 return
             }
-            // Buffer set successfully — now paste it into the focused pane
-            self.sendCommandFireAndForget("paste-buffer -t %\(paneId)")
-            logger.info("Pasted clipboard to tmux pane %\(paneId) (\(clipboardContent.count) chars)")
+            // Buffer set successfully — now paste it into the focused pane.
+            // paneId already has the "%" prefix (e.g. "%0"), so don't add another.
+            self.sendCommandFireAndForget("paste-buffer -t \(paneId)")
+            logger.info("Pasted clipboard to tmux pane \(paneId) (\(clipboardContent.count) chars)")
         }
 
         if !surface.sendTmuxCommand("set-buffer -- \"\(escaped)\"") {