Pin git commands to the repo they were created for

Lazygit changes the process working directory when switching repos, but
work that is still in flight for the previous repo can keep spawning
git commands after the switch — most notably a background refresh. Its
model writes are already dropped by the repo generation guard, but its
git commands would now run against the new repo. That is wasted work at
best; at worst it surfaces spurious error popups (the behind-base-
branch computation failing with "no such ref" when the old repo's main
branch doesn't exist in the new one) and pollutes caches belonging to
the old repo's reusable state (e.g. MainBranches' existing-branches
cache), which the user sees when switching back.

Give the git command builder the directory of the repo it was created
for, and pin every command it produces to that directory. The pinned
directory and the process cwd are identical until a switch happens
(NewGitCommand chdirs to the worktree path right before creating the
builder), so nothing changes in the steady state; the pin only takes
effect for commands built through a previous repo's GitCommand instance
after a switch, which now keep addressing the repo they were built for.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pkg/commands/git.go

@@ -90,7 +90,7 @@ func NewGitCommandAux(
 	repoPaths *git_commands.RepoPaths,
 	pagerConfig *config.PagerConfig,
 ) *GitCommand {
-	cmd := NewGitCmdObjBuilder(cmn.Log, osCommand.Cmd)
+	cmd := NewGitCmdObjBuilder(cmn.Log, osCommand.Cmd, repoPaths.WorktreePath())
 
 	// here we're doing a bunch of dependency injection for each of our commands structs.
 	// This is admittedly messy, but allows us to test each command struct in isolation,

pkg/commands/git_cmd_obj_builder.go

@@ -11,6 +11,15 @@ import (
 
 type gitCmdObjBuilder struct {
 	innerBuilder *oscommands.CmdObjBuilder
+
+	// The directory of the repo (or worktree) this builder was created for;
+	// every command we produce runs there, regardless of the process's current
+	// working directory. The two are the same until the user switches to
+	// another repo: lazygit chdirs on a switch, but work still in flight for
+	// the previous repo (e.g. a background refresh spawning commands through
+	// the old builder) must keep running its commands against the repo it
+	// started in, not whichever one the process has since moved to.
+	repoDir string
 }
 
 var _ oscommands.ICmdObjBuilder = &gitCmdObjBuilder{}
@@ -21,7 +30,7 @@ var _ oscommands.ICmdObjBuilder = &gitCmdObjBuilder{}
 // only the foreground files refresh) opt back in via CmdObj.RemoveEnvVar.
 var defaultEnvVar = git_commands.OptionalLocksEnvVar + "=0"
 
-func NewGitCmdObjBuilder(log *logrus.Entry, innerBuilder *oscommands.CmdObjBuilder) *gitCmdObjBuilder {
+func NewGitCmdObjBuilder(log *logrus.Entry, innerBuilder *oscommands.CmdObjBuilder, repoDir string) *gitCmdObjBuilder {
 	// the price of having a convenient interface where we can say .New(...).Run() is that our builder now depends on our runner, so when we want to wrap the default builder/runner in new functionality we need to jump through some hoops. We could avoid the use of a decorator function here by just exporting the runner field on the default builder but that would be misleading because we don't want anybody using that to run commands (i.e. we want there to be a single API used across the codebase)
 	updatedBuilder := innerBuilder.CloneWithNewRunner(func(runner oscommands.ICmdObjRunner) oscommands.ICmdObjRunner {
 		return &gitCmdObjRunner{
@@ -33,15 +42,16 @@ func NewGitCmdObjBuilder(log *logrus.Entry, innerBuilder *oscommands.CmdObjBuild
 
 	return &gitCmdObjBuilder{
 		innerBuilder: updatedBuilder,
+		repoDir:      repoDir,
 	}
 }
 
 func (self *gitCmdObjBuilder) New(args []string) *oscommands.CmdObj {
-	return self.innerBuilder.New(args).AddEnvVars(defaultEnvVar)
+	return self.innerBuilder.New(args).AddEnvVars(defaultEnvVar).SetWd(self.repoDir)
 }
 
 func (self *gitCmdObjBuilder) NewShell(cmdStr string, shellFunctionsFile string) *oscommands.CmdObj {
-	return self.innerBuilder.NewShell(cmdStr, shellFunctionsFile).AddEnvVars(defaultEnvVar)
+	return self.innerBuilder.NewShell(cmdStr, shellFunctionsFile).AddEnvVars(defaultEnvVar).SetWd(self.repoDir)
 }
 
 func (self *gitCmdObjBuilder) Quote(str string) string {

pkg/commands/git_cmd_obj_builder_test.go

@@ -17,8 +17,25 @@ func TestGitCmdObjBuilderDisablesOptionalLocksByDefault(t *testing.T) {
 	builder := NewGitCmdObjBuilder(
 		utils.NewDummyLog(),
 		oscommands.NewDummyCmdObjBuilder(oscommands.NewFakeRunner(t)),
+		"/path/to/repo",
 	)
 
 	assert.Contains(t, builder.New([]string{"git", "status"}).GetEnvVars(), git_commands.OptionalLocksEnvVar+"=0")
 	assert.Contains(t, builder.NewShell("git status", "").GetEnvVars(), git_commands.OptionalLocksEnvVar+"=0")
 }
+
+// Every command the builder produces runs in the directory of the repo the
+// builder was created for, not in the process's current directory: lazygit
+// chdirs when switching repos, and commands built for the previous repo after
+// that (e.g. by a background refresh still in flight) must keep addressing the
+// repo they were built for.
+func TestGitCmdObjBuilderPinsCommandsToRepoDir(t *testing.T) {
+	builder := NewGitCmdObjBuilder(
+		utils.NewDummyLog(),
+		oscommands.NewDummyCmdObjBuilder(oscommands.NewFakeRunner(t)),
+		"/path/to/repo",
+	)
+
+	assert.Equal(t, "/path/to/repo", builder.New([]string{"git", "status"}).GetCmd().Dir)
+	assert.Equal(t, "/path/to/repo", builder.NewShell("git status", "").GetCmd().Dir)
+}