fix(keybindings): preserve valid pre-swap overrides

src/main/keybindings/keybinding-file.test.ts

@@ -263,6 +263,38 @@ describe('keybinding-file', () => {
     })
   })
 
+  it('preserves pre-swap customizations that conflict only with the new defaults', () => {
+    // This was valid before the swap: moving nextSameType to Mod+K freed its
+    // old Shift+] chord for previousSameType. The new registry temporarily
+    // assigns Shift+] to nextAllTypes, but the seed must not mistake the
+    // resulting conflict for an absent user override and replace it.
+    writeFileSync(
+      filePath,
+      JSON.stringify({
+        version: 1,
+        platforms: {
+          darwin: {
+            'tab.nextSameType': ['Mod+K'],
+            'tab.previousSameType': ['Mod+Shift+BracketRight']
+          }
+        }
+      }),
+      'utf8'
+    )
+
+    seedLegacyTabSwitchBindings(filePath, 'darwin', LEGACY_TAB_SWITCH_BINDINGS)
+
+    expect(readKeybindingFile(filePath, 'darwin')).toMatchObject({
+      overrides: {
+        'tab.nextSameType': ['Mod+K'],
+        'tab.previousSameType': ['Mod+Shift+BracketRight'],
+        'tab.nextAllTypes': ['Mod+Alt+BracketRight'],
+        'tab.previousAllTypes': ['Mod+Alt+BracketLeft']
+      },
+      diagnostics: []
+    })
+  })
+
   it('is a no-op once every swapped action already resolves on this platform', () => {
     // Seeding writes the whole document at once, so it clears the per-write
     // conflict guard that a naive one-action-at-a-time write would trip.

src/main/keybindings/keybinding-file.ts

@@ -340,12 +340,14 @@ export function seedLegacyTabSwitchBindings(
   const keybindingPlatform = getKeybindingPlatform(platform)
   const actionIds = Object.keys(legacyBindings) as KeybindingActionId[]
   const current = readKeybindingFile(path, platform)
-  // `current.overrides` is the effective override map for this platform (common
-  // + this platform's section). Skip any action that already resolves to a
-  // user-set binding here; a foreign-platform-only override must not block the
-  // pin, or this platform would drift to the new default.
+  const activePlatformOverrides = current.platformOverrides[keybindingPlatform] ?? {}
+  // Why: the new defaults can temporarily make a valid pre-swap customization
+  // look conflicting and remove it from `current.overrides`. Inspect the parsed
+  // common + active-platform sections directly so the seed never replaces it.
   const toSeed = actionIds.filter(
-    (actionId) => !Object.prototype.hasOwnProperty.call(current.overrides, actionId)
+    (actionId) =>
+      !Object.prototype.hasOwnProperty.call(current.commonOverrides, actionId) &&
+      !Object.prototype.hasOwnProperty.call(activePlatformOverrides, actionId)
   )
   if (toSeed.length === 0) {
     return { seeded: false, snapshot: current }