jesseduffield.lazygit/pkg/gui/controllers/helpers/patch_building_helper.go
Stefan Haller cf8e5fd27e Recover diff-line identity by parsing the buffer, behind a swappable seam
The focused main view's click/enter/e/G handlers all need the same thing: given
a rendered diff row, the patch-space line it corresponds to. Until now that came
solely from delta's lazygit-edit:// hyperlinks, which only carry a path and a
single line number — no side. That's lossy: for a deletion the number is the old
line, but the consumers fed it into new-file lookups, and two consecutive
deletions (which share a new-file line number) couldn't be told apart at all.

Replace GetFileAndLineForClickedDiffLine with GetDiffLineInfo, returning the
fuller (file, type, new-line, old-line) record from diff-line-metadata-notes.md.
This is mechanism #1: parse the decolorized view buffer — walk up to the file's
"diff --git" section, reuse patch.Parse on it (splitting multi-file commit diffs
on the "diff --git" boundaries), and read the type and line numbers off the patch
arithmetic. It serves the structure-preserving renderings — no pager, git diff
--color, and delta --color-only without line numbers — with no external
dependency.

To avoid trusting a mis-parse, the parser bails when a hunk's body no longer
matches its header (Patch.IsWellFormed). That's what happens when a pager keeps
the diff/hunk headers but restructures the body: delta's line-number gutters push
the +/- marker off the start of each line, so every body line reads as context.
Such renderings fall through to the next backend rather than yielding a confident
wrong answer. (diff-so-fancy goes further and rewrites the headers too, so it
fails even earlier, on the missing "diff --git".)

GetDiffLineInfo is a seam with swappable backends: the buffer parser first, then
the old hyperlink reader as a fallback for renderings the parser can't handle
(delta's default mode, or delta with line-number gutters). The future #2 OSC
per-cell metadata reader plugs in ahead of both, behind the same record shape.

Wire the consumers to the record per that doc's field mapping:
- dive into staging/patch building lands on the exact patch line, looking a
  deletion up by its old-file line number (PatchLineForOldLineNumber) so the
  two-deletions case resolves correctly;
- `e` edits at the new-file line;
- `G` anchors the PR link on the left (old) side for a deletion, the right (new)
  side otherwise.

The hyperlink fallback can't convey the side, so it reports DiffLineOther, which
the consumers treat as a non-deletion — i.e. exactly today's behavior.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-08-08 12:58:59 +02:00

185 lines
6.1 KiB
Go

package helpers
import (
"fmt"
"github.com/jesseduffield/lazygit/pkg/commands/patch"
"github.com/jesseduffield/lazygit/pkg/gui/patch_exploring"
"github.com/jesseduffield/lazygit/pkg/gui/types"
)
type PatchBuildingHelper struct {
c *HelperCommon
}
func NewPatchBuildingHelper(
c *HelperCommon,
) *PatchBuildingHelper {
return &PatchBuildingHelper{
c: c,
}
}
func (self *PatchBuildingHelper) ShowHunkStagingHint() {
if !self.c.AppState.DidShowHunkStagingHint && self.c.UserConfig().Gui.UseHunkModeInStagingView {
self.c.AppState.DidShowHunkStagingHint = true
self.c.SaveAppStateAndLogError()
message := fmt.Sprintf(self.c.Tr.HunkStagingHint, self.c.UserConfig().Keybinding.Main.ToggleSelectHunk)
self.c.Confirm(types.ConfirmOpts{
Prompt: message,
})
}
}
// takes us from the patch building panel back to the commit files panel, or to
// the focused main view if that's where we entered it from
func (self *PatchBuildingHelper) Escape() {
EscapeFromPatchExplorer(self.c, self.c.Contexts().CustomPatchBuilder)
}
// EscapeFromPatchExplorer returns from a patch explorer context (staging or
// patch building). If we entered it from a focused main view, we go back to
// where we came from (re-rendering the side panel's content into the main view,
// like the plain escape does), then focus the main view and restore its scroll
// position and selection. Otherwise we just pop to the side panel.
func EscapeFromPatchExplorer(c *HelperCommon, context types.IPatchExplorerContext) {
snapshot := context.GetFocusedMainViewSnapshot()
if snapshot == nil {
c.Context().Pop()
return
}
context.SetFocusedMainViewSnapshot(nil)
// Restore the side panel's selection before we render it, so it shows the
// same content the main view had (diving into staging can change it, e.g.
// from a directory to a file in the files panel).
if listContext, ok := snapshot.SidePanel.(types.IListContext); ok && snapshot.SidePanelSelectedLineIdx >= 0 {
listContext.GetList().SetSelectedLineIdx(snapshot.SidePanelSelectedLineIdx)
}
view := snapshot.MainView.GetView()
// Ask the upcoming re-render to restore the scroll position. Pushing the side
// panel re-renders its content into the main view via a cmd/pty task. Until
// that content is ready, the main view keeps showing the placeholder that
// CopyContent left in it (the view we're leaving) at its current scroll; the
// task then scrolls to the saved position as part of the first paint that
// shows the real content. Doing it this way (rather than setting the origin up
// front) avoids both a jump to the top and a misplaced placeholder frame.
if manager := c.GetViewBufferManagerForView(view); manager != nil {
manager.ScrollToOriginYForNextTask(snapshot.OriginY)
}
// Land on the side panel first (this re-renders the original content into the
// main view), then focus the main view on top of it.
c.Context().Push(snapshot.SidePanel, types.OnFocusOpts{})
c.Context().Push(snapshot.MainView, types.OnFocusOpts{})
restore := func() {
view.FocusPoint(0, snapshot.SelectedLineIdx, false)
view.Highlight = true
view.HighlightInactive = false
}
// The scroll position is handled by the re-render above, but the selection
// still needs the content loaded down to the selected line, which happens
// asynchronously. Wait until the diff has been fully read before restoring
// it. We do this on the next UI tick, by which point the re-render task is
// live and ReadToEnd can hook into it.
c.OnUIThread(func() error {
manager := c.GetViewBufferManagerForView(view)
if manager == nil {
restore()
return nil
}
manager.ReadToEnd(func() {
c.OnUIThread(func() error {
restore()
return nil
})
})
return nil
})
}
// kills the custom patch and returns us back to the commit files panel if needed
func (self *PatchBuildingHelper) Reset() error {
self.c.Git().Patch.PatchBuilder.Reset()
if self.c.Context().CurrentStatic().GetKind() != types.SIDE_CONTEXT {
self.Escape()
}
self.c.Refresh(types.RefreshOptions{
Scope: []types.RefreshableView{types.COMMIT_FILES},
})
// refreshing the current context so that the secondary panel is hidden if necessary.
self.c.PostRefreshUpdate(self.c.Context().Current())
return nil
}
func (self *PatchBuildingHelper) RefreshPatchBuildingPanel(opts types.OnFocusOpts) {
selectedLineIdx := -1
selectedRealLineIdx := -1
if opts.ClickedWindowName == "main" {
selectedLineIdx = opts.ClickedViewLineIdx
selectedRealLineIdx = opts.ClickedViewRealLineIdx
}
if !self.c.Git().Patch.PatchBuilder.Active() {
self.Escape()
return
}
// get diff from commit file that's currently selected
file := self.c.Contexts().CommitFiles.GetSelectedFile()
if file == nil {
return
}
from, to := self.c.Contexts().CommitFiles.GetFromAndToForDiff()
from, reverse := self.c.Modes().Diffing.GetFromAndReverseArgsForDiff(from)
diff, err := self.c.Git().WorkingTree.ShowFileDiff(from, to, reverse, file.Path, file.PreviousPath, true)
if err != nil {
return
}
secondaryDiff := self.c.Git().Patch.PatchBuilder.RenderPatchForFile(patch.RenderPatchForFileOpts{
Filename: file.Path,
PreviousPath: file.PreviousPath,
Plain: false,
Reverse: false,
TurnAddedFilesIntoDiffAgainstEmptyFile: true,
})
context := self.c.Contexts().CustomPatchBuilder
oldState := context.GetState()
state := patch_exploring.NewState(diff, selectedLineIdx, selectedRealLineIdx, opts.ClickedViewRealLineIsDeletion, context.GetView(), oldState, self.c.UserConfig().Gui.UseHunkModeInStagingView, opts.SelectLineInDefaultMode)
context.SetState(state)
if state == nil {
self.Escape()
return
}
mainContent := context.GetContentToRender()
self.c.Contexts().CustomPatchBuilder.FocusSelection()
self.c.RenderToMainViews(types.RefreshMainOpts{
Pair: self.c.MainViewPairs().PatchBuilding,
Main: &types.ViewUpdateOpts{
Task: types.NewRenderStringWithoutScrollTask(mainContent),
Title: self.c.Tr.Patch,
},
Secondary: &types.ViewUpdateOpts{
Task: types.NewRenderStringWithoutScrollTask(secondaryDiff),
Title: self.c.Tr.CustomPatch,
},
})
}