guard prefix and wine edits while their apps run

src/ipc/index.js

@@ -85,7 +85,15 @@ function registerIpc({ getWindow, onGamesChanged }) {
   ipcMain.handle('wines:setDisabled', (e, id, disabled) => wines.setWineDisabled(id, disabled))
   ipcMain.handle('wines:setDisplayName', (e, id, name) => wines.setWineDisplayName(id, name))
   ipcMain.handle('wines:setDefault', (e, id) => wines.setDefaultWine(id))
-  ipcMain.handle('wines:delete', (e, id) => wines.deleteWine(id))
+  ipcMain.handle('wines:delete', (e, id) => {
+    // the build's files back the running prefix (dlls, stub exes) - deleting
+    // it under a running game breaks that game
+    if (library.isWineInUse(id, games.runningInfo())) {
+      const apps = games.runningInfo().filter(r => r.wine === id).map(r => r.name)
+      return { ok: false, error: 'inUse', apps }
+    }
+    return wines.deleteWine(id)
+  })
   ipcMain.handle('wines:import', async (e, srcDir) => {
     try {
       return await wines.importWineFolder(srcDir)
@@ -95,11 +103,37 @@ function registerIpc({ getWindow, onGamesChanged }) {
   })
 
   // prefixes ---------------------------------------------------------------------
+  // A prefix folder must not move or disappear while a game runs in it: wine
+  // keeps the registry and user files open and would write into a folder that
+  // no longer exists (or, for a delete, lose them mid-run). The renderer shows
+  // these as a toast naming the blocking app.
+  const prefixInUse = name => {
+    const apps = library.appsUsingPrefix(name, games.runningInfo())
+    return apps.length ? { ok: false, error: 'inUse', apps: apps.map(r => r.name) } : null
+  }
   ipcMain.handle('prefixes:list', () => prefixes.listPrefixes())
   ipcMain.handle('prefixes:create', (e, name) => prefixes.createPrefix(name))
-  ipcMain.handle('prefixes:delete', (e, name) => prefixes.deletePrefix(name))
-  ipcMain.handle('prefixes:rename', (e, oldName, newName) => prefixes.renamePrefix(oldName, newName))
-  ipcMain.handle('prefixes:setDefault', (e, name) => prefixes.setDefaultPrefix(name))
+  ipcMain.handle('prefixes:delete', (e, name) => {
+    const busy = prefixInUse(name)
+    if (busy) return busy
+    // deleting a prefix that still has apps registered in it would orphan
+    // them (they fall back to the default prefix and lose their files)
+    const users = library.gamesUsingPrefix(name).map(g => g.name)
+    if (users.length) return { ok: false, error: 'hasApps', apps: users }
+    return prefixes.deletePrefix(name)
+  })
+  ipcMain.handle('prefixes:rename', (e, oldName, newName) => prefixInUse(oldName) || prefixes.renamePrefix(oldName, newName))
+  ipcMain.handle('prefixes:setDefault', (e, name) => {
+    // apps without a prefix field of their own resolve the default at launch;
+    // switching it now would silently move their next run (a prefix import is
+    // pinned to its own name)
+    const defs = prefixes.listPrefixes()
+    if (name !== defs.default) {
+      const affected = library.gamesFollowingDefault(games.runningInfo())
+      if (affected.length) return { ok: false, error: 'inUse', apps: affected.map(r => r.name) }
+    }
+    return prefixes.setDefaultPrefix(name)
+  })
 
   // games: library -----------------------------------------------------------------
   ipcMain.handle('games:list', () => library.loadGames())