Make cancel from CatFileBatch and CatFileBatchCheck wait for the command to end (#16479)

Fix #16427 (again!)

* handle sharing violation error code

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: Lauris BH <lauris@nix.lv>

modules/git/batch_reader.go

@@ -7,6 +7,7 @@ package git
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"io"
 	"math"
 	"strconv"
@@ -28,16 +29,20 @@ type WriteCloserError interface {
 func CatFileBatchCheck(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
 	batchStdinReader, batchStdinWriter := io.Pipe()
 	batchStdoutReader, batchStdoutWriter := io.Pipe()
+	ctx, ctxCancel := context.WithCancel(DefaultContext)
+	closed := make(chan struct{})
 	cancel := func() {
 		_ = batchStdinReader.Close()
 		_ = batchStdinWriter.Close()
 		_ = batchStdoutReader.Close()
 		_ = batchStdoutWriter.Close()
+		ctxCancel()
+		<-closed
 	}
 
 	go func() {
 		stderr := strings.Builder{}
-		err := NewCommand("cat-file", "--batch-check").RunInDirFullPipeline(repoPath, batchStdoutWriter, &stderr, batchStdinReader)
+		err := NewCommandContext(ctx, "cat-file", "--batch-check").RunInDirFullPipeline(repoPath, batchStdoutWriter, &stderr, batchStdinReader)
 		if err != nil {
 			_ = batchStdoutWriter.CloseWithError(ConcatenateError(err, (&stderr).String()))
 			_ = batchStdinReader.CloseWithError(ConcatenateError(err, (&stderr).String()))
@@ -45,6 +50,7 @@ func CatFileBatchCheck(repoPath string) (WriteCloserError, *bufio.Reader, func()
 			_ = batchStdoutWriter.Close()
 			_ = batchStdinReader.Close()
 		}
+		close(closed)
 	}()
 
 	// For simplicities sake we'll use a buffered reader to read from the cat-file --batch-check
@@ -59,16 +65,20 @@ func CatFileBatch(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
 	// so let's create a batch stdin and stdout
 	batchStdinReader, batchStdinWriter := io.Pipe()
 	batchStdoutReader, batchStdoutWriter := nio.Pipe(buffer.New(32 * 1024))
+	ctx, ctxCancel := context.WithCancel(DefaultContext)
+	closed := make(chan struct{})
 	cancel := func() {
 		_ = batchStdinReader.Close()
 		_ = batchStdinWriter.Close()
 		_ = batchStdoutReader.Close()
 		_ = batchStdoutWriter.Close()
+		ctxCancel()
+		<-closed
 	}
 
 	go func() {
 		stderr := strings.Builder{}
-		err := NewCommand("cat-file", "--batch").RunInDirFullPipeline(repoPath, batchStdoutWriter, &stderr, batchStdinReader)
+		err := NewCommandContext(ctx, "cat-file", "--batch").RunInDirFullPipeline(repoPath, batchStdoutWriter, &stderr, batchStdinReader)
 		if err != nil {
 			_ = batchStdoutWriter.CloseWithError(ConcatenateError(err, (&stderr).String()))
 			_ = batchStdinReader.CloseWithError(ConcatenateError(err, (&stderr).String()))
@@ -76,6 +86,7 @@ func CatFileBatch(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
 			_ = batchStdoutWriter.Close()
 			_ = batchStdinReader.Close()
 		}
+		close(closed)
 	}()
 
 	// For simplicities sake we'll us a buffered reader to read from the cat-file --batch

modules/util/remove.go

@@ -6,10 +6,13 @@ package util
 
 import (
 	"os"
+	"runtime"
 	"syscall"
 	"time"
 )
 
+const windowsSharingViolationError syscall.Errno = 32
+
 // Remove removes the named file or (empty) directory with at most 5 attempts.
 func Remove(name string) error {
 	var err error
@@ -25,6 +28,12 @@ func Remove(name string) error {
 			continue
 		}
 
+		if unwrapped == windowsSharingViolationError && runtime.GOOS == "windows" {
+			// try again
+			<-time.After(100 * time.Millisecond)
+			continue
+		}
+
 		if unwrapped == syscall.ENOENT {
 			// it's already gone
 			return nil
@@ -48,6 +57,12 @@ func RemoveAll(name string) error {
 			continue
 		}
 
+		if unwrapped == windowsSharingViolationError && runtime.GOOS == "windows" {
+			// try again
+			<-time.After(100 * time.Millisecond)
+			continue
+		}
+
 		if unwrapped == syscall.ENOENT {
 			// it's already gone
 			return nil
@@ -71,6 +86,12 @@ func Rename(oldpath, newpath string) error {
 			continue
 		}
 
+		if unwrapped == windowsSharingViolationError && runtime.GOOS == "windows" {
+			// try again
+			<-time.After(100 * time.Millisecond)
+			continue
+		}
+
 		if i == 0 && os.IsNotExist(err) {
 			return err
 		}