fix(navigation): preserve jumplist before output buffer jumps (#456)

Problem: programmatic cursor moves via nvim_win_set_cursor in the
output window (gg, ]], [[, ]u, [u, <CR>, ...) do not update the
previous-position mark, so users cannot return to the prior output
location with `` or <C-o> after a jump.

Solution: introduce mark_jump_position() which records the current
cursor as the ' mark inside the source window via
`noau normal! m'`, and call it before every nvim_win_set_cursor in
navigation.lua and before the gg keymap in output_window.lua.

Author: phanen

lua/opencode/ui/navigation.lua

@@ -4,6 +4,13 @@ local state = require('opencode.state')
 local config = require('opencode.config')
 local renderer = require('opencode.ui.renderer')
 
+---@param win integer
+local function mark_jump_position(win)
+  pcall(vim.api.nvim_win_call, win, function()
+    vim.cmd([[noau normal! m']])
+  end)
+end
+
 function M.goto_message_by_id(message_id)
   require('opencode.ui.ui').focus_output()
   local windows = state.windows or {}
@@ -18,6 +25,7 @@ function M.goto_message_by_id(message_id)
   if not rendered_msg or not rendered_msg.line_start then
     return
   end
+  mark_jump_position(win)
   vim.api.nvim_win_set_cursor(win, { rendered_msg.line_start + 1, 0 })
 end
 
@@ -34,11 +42,13 @@ function M.goto_next_message()
   local current_line = vim.api.nvim_win_get_cursor(win)[1]
   local next_message = renderer.get_next_rendered_message(current_line)
   if next_message and next_message.line_start then
+    mark_jump_position(win)
     vim.api.nvim_win_set_cursor(win, { next_message.line_start + 1, 0 })
     return
   end
 
   local line_count = vim.api.nvim_buf_line_count(buf)
+  mark_jump_position(win)
   vim.api.nvim_win_set_cursor(win, { line_count, 0 })
 end
 
@@ -55,10 +65,12 @@ function M.goto_prev_message()
   local current_line = vim.api.nvim_win_get_cursor(win)[1]
   local previous_message = renderer.get_prev_rendered_message(current_line)
   if previous_message and previous_message.line_start then
+    mark_jump_position(win)
     vim.api.nvim_win_set_cursor(win, { previous_message.line_start + 1, 0 })
     return
   end
 
+  mark_jump_position(win)
   vim.api.nvim_win_set_cursor(win, { 1, 0 })
 end
 
@@ -79,6 +91,7 @@ function M.goto_next_user_message()
   local current_line = vim.api.nvim_win_get_cursor(win)[1]
   local next_message = renderer.get_next_user_message(current_line)
   if next_message and next_message.line_start then
+    mark_jump_position(win)
     vim.api.nvim_win_set_cursor(win, { next_message.line_start + 1, 0 })
     return
   end
@@ -101,6 +114,7 @@ function M.goto_prev_user_message()
   local current_line = vim.api.nvim_win_get_cursor(win)[1]
   local previous_message = renderer.get_prev_user_message(current_line)
   if previous_message and previous_message.line_start then
+    mark_jump_position(win)
     vim.api.nvim_win_set_cursor(win, { previous_message.line_start + 1, 0 })
     return
   end
@@ -153,6 +167,7 @@ local function open_at(win, path, line, col)
       local line_text = target_lines[1] or ''
       target_col = math.max(0, math.min(col - 1, math.max(#line_text - 1, 0)))
     end
+    mark_jump_position(win)
     pcall(vim.api.nvim_win_set_cursor, win, { target_line, target_col })
     vim.cmd('normal! zz')
   end

lua/opencode/ui/output_window.lua

@@ -677,6 +677,7 @@ function M.setup_keymaps(windows)
   vim.keymap.set('n', 'gg', function()
     local renderer = require('opencode.ui.renderer')
     renderer.load_all_messages()
+    pcall(vim.cmd, [[noau normal! m']])
     vim.api.nvim_win_set_cursor(0, { 1, 0 })
   end, { buffer = windows.output_buf })
 end

tests/unit/navigation_spec.lua

@@ -539,3 +539,120 @@ describe('output token navigation', function()
     assert.same({ 2, 3 }, vim.api.nvim_win_get_cursor(state.windows.output_win))
   end)
 end)
+
+describe('navigation jumplist preservation', function()
+  local output_buf, output_win, input_buf, input_win, code_buf, code_win
+  local original_windows, original_code_win, original_code_buf, original_config
+
+  before_each(function()
+    original_windows = state.store.get('windows')
+    original_code_win = state.store.get('last_code_win_before_opencode')
+    original_code_buf = state.store.get('current_code_buf')
+    original_config = vim.deepcopy(config.values)
+    state.ui.clear_hidden_window_state()
+
+    code_buf = vim.api.nvim_create_buf(false, true)
+    vim.api.nvim_buf_set_lines(code_buf, 0, -1, false, { 'alpha', 'beta', 'gamma' })
+    code_win = vim.api.nvim_open_win(code_buf, true, {
+      relative = 'editor',
+      width = 40,
+      height = 5,
+      row = 0,
+      col = 0,
+    })
+
+    output_buf = vim.api.nvim_create_buf(false, true)
+    output_win = vim.api.nvim_open_win(output_buf, true, {
+      relative = 'editor',
+      width = 80,
+      height = 8,
+      row = 6,
+      col = 0,
+    })
+
+    state.ui.set_windows({ output_buf = output_buf, output_win = output_win })
+    state.ui.set_last_code_window(code_win)
+  end)
+
+  after_each(function()
+    state.ui.clear_hidden_window_state()
+    pcall(vim.api.nvim_win_close, output_win, true)
+    pcall(vim.api.nvim_win_close, input_win, true)
+    pcall(vim.api.nvim_win_close, code_win, true)
+    pcall(vim.api.nvim_buf_delete, output_buf, { force = true })
+    pcall(vim.api.nvim_buf_delete, input_buf, { force = true })
+    pcall(vim.api.nvim_buf_delete, code_buf, { force = true })
+
+    if original_windows ~= nil then
+      state.ui.set_windows(original_windows)
+    else
+      state.ui.clear_windows()
+    end
+    state.ui.set_last_code_window(original_code_win)
+    state.ui.set_current_code_buf(original_code_buf)
+    config.values = original_config
+  end)
+
+  it('marks the output cursor before goto_next_message moves', function()
+    local renderer = require('opencode.ui.renderer')
+    local ctx = require('opencode.ui.renderer.ctx')
+    state.renderer.set_messages({
+      { info = { id = 'm1', role = 'user' } },
+      { info = { id = 'm2', role = 'assistant' } },
+    })
+    ctx.render_state:set_message({ info = { id = 'm1', role = 'user' } }, 1, 1)
+    ctx.render_state:set_message({ info = { id = 'm2', role = 'assistant' } }, 20, 20)
+    vim.api.nvim_buf_set_lines(output_buf, 0, -1, false, vim.fn['repeat']({ 'line' }, 40))
+    vim.api.nvim_win_set_cursor(output_win, { 5, 0 })
+    vim.api.nvim_buf_set_mark(output_buf, "'", 1, 0, {})
+
+    navigation.goto_next_message()
+
+    local mark = vim.api.nvim_buf_get_mark(output_buf, "'")
+    assert.equals(5, mark[1])
+    assert.equals(0, mark[2])
+  end)
+
+  it('marks the output cursor before goto_prev_message moves', function()
+    local renderer = require('opencode.ui.renderer')
+    local ctx = require('opencode.ui.renderer.ctx')
+    state.renderer.set_messages({
+      { info = { id = 'm1', role = 'user' } },
+      { info = { id = 'm2', role = 'assistant' } },
+    })
+    ctx.render_state:set_message({ info = { id = 'm1', role = 'user' } }, 1, 1)
+    ctx.render_state:set_message({ info = { id = 'm2', role = 'assistant' } }, 20, 20)
+    vim.api.nvim_buf_set_lines(output_buf, 0, -1, false, vim.fn['repeat']({ 'line' }, 40))
+    vim.api.nvim_win_set_cursor(output_win, { 31, 0 })
+    vim.api.nvim_buf_set_mark(output_buf, "'", 1, 0, {})
+
+    navigation.goto_prev_message()
+
+    local mark = vim.api.nvim_buf_get_mark(output_buf, "'")
+    assert.equals(31, mark[1])
+    assert.equals(0, mark[2])
+  end)
+
+  it('marks the output cursor before jumping to a rendered file target', function()
+    vim.api.nvim_buf_set_lines(output_buf, 0, -1, false, { existing_path })
+    vim.api.nvim_win_set_cursor(output_win, { 1, 0 })
+    vim.api.nvim_buf_set_mark(output_buf, "'", 1, 0, {})
+    local original_navigate = navigation.navigate_to_location
+    navigation.navigate_to_location = function()
+      return true
+    end
+    stub(renderer, 'get_target_at_position').returns({
+      kind = 'file',
+      path = existing_path,
+      line = 1,
+      col = 1,
+    })
+
+    navigation.jump_to_target_at_cursor()
+
+    navigation.navigate_to_location = original_navigate
+    local mark = vim.api.nvim_buf_get_mark(output_buf, "'")
+    assert.equals(1, mark[1])
+    assert.equals(0, mark[2])
+  end)
+end)

tests/unit/navigation_user_message_spec.lua

@@ -333,4 +333,46 @@ describe('navigation user message jumps', function()
       assert.equals(2, cursor[1])
     end)
   end)
+
+  describe('jumplist preservation', function()
+    it('marks the previous position before jumping to the next user message', function()
+      seed({
+        { info = { id = 'u1', role = 'user' } },
+        { info = { id = 'a1', role = 'assistant' } },
+        { info = { id = 'u2', role = 'user' } },
+      }, {
+        { id = 'u1', role = 'user', line_start = 1 },
+        { id = 'a1', role = 'assistant', line_start = 20 },
+        { id = 'u2', role = 'user', line_start = 40 },
+      })
+
+      vim.api.nvim_win_set_cursor(output_win, { 5, 0 })
+      vim.api.nvim_buf_set_mark(output_buf, "'", 1, 0, {})
+      navigation.goto_next_user_message()
+
+      local mark = vim.api.nvim_buf_get_mark(output_buf, "'")
+      assert.equals(5, mark[1])
+      assert.equals(0, mark[2])
+    end)
+
+    it('marks the previous position before jumping to the previous user message', function()
+      seed({
+        { info = { id = 'u1', role = 'user' } },
+        { info = { id = 'a1', role = 'assistant' } },
+        { info = { id = 'u2', role = 'user' } },
+      }, {
+        { id = 'u1', role = 'user', line_start = 1 },
+        { id = 'a1', role = 'assistant', line_start = 20 },
+        { id = 'u2', role = 'user', line_start = 40 },
+      })
+
+      vim.api.nvim_win_set_cursor(output_win, { 81, 0 })
+      vim.api.nvim_buf_set_mark(output_buf, "'", 1, 0, {})
+      navigation.goto_prev_user_message()
+
+      local mark = vim.api.nvim_buf_get_mark(output_buf, "'")
+      assert.equals(81, mark[1])
+      assert.equals(0, mark[2])
+    end)
+  end)
 end)