From 7731311674bbb5eb171b7d59b40dfd0e5a6cbc84 Mon Sep 17 00:00:00 2001
From: Brandon <brandondong96@gmail.com>
Date: Tue, 4 Feb 2025 17:11:09 -0800
Subject: [PATCH] Don't try killing processes if we already know the command
 finished

This may lead to unrelated processes being killed on Windows (https://github.com/jesseduffield/lazygit/issues/3008). Imagine:
1. lazygit is started and runs git diff in process X which completes immediately and exits.
2. lazygit is left in the background for several hours by which process X pid is reused by an unrelated process.
3. lazygit is focused back on and runs another git diff. It first runs this stop logic which will kill process X and its children.
---
 pkg/tasks/tasks.go | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/pkg/tasks/tasks.go b/pkg/tasks/tasks.go
index e80b63a2a..b488152a5 100644
--- a/pkg/tasks/tasks.go
+++ b/pkg/tasks/tasks.go
@@ -137,21 +137,31 @@ func (self *ViewBufferManager) NewCmdTask(start func() (*exec.Cmd, io.Reader), p
 		cmd, r := start()
 		timeToStart := time.Since(startTime)
 
-		go utils.Safe(func() {
-			<-opts.Stop
-			// we use the time it took to start the program as a way of checking if things
-			// are running slow at the moment. This is admittedly a crude estimate, but
-			// the point is that we only want to throttle when things are running slow
-			// and the user is flicking through a bunch of items.
-			self.throttle = time.Since(startTime) < THROTTLE_TIME && timeToStart > COMMAND_START_THRESHOLD
-			if err := oscommands.Kill(cmd); err != nil {
-				if !strings.Contains(err.Error(), "process already finished") {
-					self.Log.Errorf("error when running cmd task: %v", err)
-				}
-			}
+		done := make(chan struct{})
 
-			// for pty's we need to call onDone here so that cmd.Wait() doesn't block forever
-			onDone()
+		go utils.Safe(func() {
+			select {
+			case <-done:
+				// The command finished and did not have to be preemptively stopped before the next command.
+				// No need to throttle.
+				self.throttle = false
+			case <-opts.Stop:
+				// we use the time it took to start the program as a way of checking if things
+				// are running slow at the moment. This is admittedly a crude estimate, but
+				// the point is that we only want to throttle when things are running slow
+				// and the user is flicking through a bunch of items.
+				self.throttle = time.Since(startTime) < THROTTLE_TIME && timeToStart > COMMAND_START_THRESHOLD
+
+				// Kill the still-running command.
+				if err := oscommands.Kill(cmd); err != nil {
+					if !strings.Contains(err.Error(), "process already finished") {
+						self.Log.Errorf("error when trying to kill cmd task: %v; Command: %v %v", err, cmd.Path, cmd.Args)
+					}
+				}
+
+				// for pty's we need to call onDone here so that cmd.Wait() doesn't block forever
+				onDone()
+			}
 		})
 
 		loadingMutex := deadlock.Mutex{}
@@ -159,8 +169,6 @@ func (self *ViewBufferManager) NewCmdTask(start func() (*exec.Cmd, io.Reader), p
 		// not sure if it's the right move to redefine this or not
 		self.readLines = make(chan LinesToRead, 1024)
 
-		done := make(chan struct{})
-
 		scanner := bufio.NewScanner(r)
 		scanner.Split(utils.ScanLinesAndTruncateWhenLongerThanBuffer(bufio.MaxScanTokenSize))