fix: Don't delete buffers that are in use in other views (fixes #291)

Author: sindrets

lua/diffview/events.lua

@@ -49,7 +49,7 @@ end
 
 ---Subscribe to a given event.
 ---@param event_id any Event identifier.
----@param callback fun(event: Event, ...)
+---@param callback fun(event: Event, ...): boolean?
 function EventEmitter:on(event_id, callback)
   if not self.event_map[event_id] then
     self.event_map[event_id] = {}
@@ -66,7 +66,7 @@ end
 
 ---Subscribe a one-shot listener to a given event.
 ---@param event_id any Event identifier.
----@param callback fun(event: Event, ...)
+---@param callback fun(event: Event, ...): boolean?
 function EventEmitter:once(event_id, callback)
   if not self.event_map[event_id] then
     self.event_map[event_id] = {}
@@ -87,7 +87,7 @@ function EventEmitter:once(event_id, callback)
 end
 
 ---Add a new any-listener, subscribed to all events.
----@param callback fun(event: Event, ...)
+---@param callback fun(event: Event, ...): boolean?
 function EventEmitter:on_any(callback)
   table.insert(self.any_listeners, 1, {
     type = "any",
@@ -99,7 +99,7 @@ function EventEmitter:on_any(callback)
 end
 
 ---Add a new one-shot any-listener, subscribed to all events.
----@param callback fun(event: Event, ...)
+---@param callback fun(event: Event, ...): boolean?
 function EventEmitter:once_any(callback)
   local emitted = false
 

lua/diffview/lib.lua

@@ -194,6 +194,23 @@ function M.get_prev_non_view_tabpage()
   end
 end
 
+---@param bufnr integer
+---@return boolean
+function M.is_buf_in_use(bufnr)
+  for _, view in ipairs(M.views) do
+    if view:instanceof(StandardView.__get()) then
+      ---@cast view StandardView
+      for _, file in ipairs(view.cur_entry.layout:files()) do
+        if file:is_valid() and file.bufnr == bufnr then
+          return true
+        end
+      end
+    end
+  end
+
+  return false
+end
+
 function M.update_colors()
   for _, view in ipairs(M.views) do
     if view:instanceof(StandardView.__get()) then

lua/diffview/vcs/file.lua

@@ -5,6 +5,7 @@ local GitRev = lazy.access("diffview.vcs.adapters.git.rev", "GitRev") ---@type G
 local RevType = lazy.access("diffview.vcs.rev", "RevType") ---@type RevType|LazyModule
 local async = lazy.require("plenary.async") ---@module "plenary.async"
 local config = lazy.require("diffview.config") ---@module "diffview.config"
+local lib = lazy.require("diffview.lib") ---@module "diffview.lib"
 local utils = lazy.require("diffview.utils") ---@module "diffview.utils"
 
 local pl = lazy.access(utils, "path") ---@type PathLib|LazyModule
@@ -107,7 +108,7 @@ function File:destroy(force)
   self.active = false
   self:detach_buffer()
 
-  if force or self.rev.type ~= RevType.LOCAL then
+  if force or self.rev.type ~= RevType.LOCAL and not lib.is_buf_in_use(self.bufnr) then
     File.safe_delete_buf(self.bufnr)
   end
 end
@@ -366,7 +367,11 @@ end
 function File:dispose_buffer()
   if self.bufnr and api.nvim_buf_is_loaded(self.bufnr) then
     self:detach_buffer()
-    File.safe_delete_buf(self.bufnr)
+
+    if not lib.is_buf_in_use(self.bufnr) then
+      File.safe_delete_buf(self.bufnr)
+    end
+
     self.bufnr = nil
   end
 end