Make cancel from CatFileBatch and CatFileBatchCheck wait for the comm…

…and to end

Fix go-gitea#16427 (again!)

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

modules/git/batch_reader.go

@@ -7,6 +7,7 @@ package git
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"io"
 	"math"
 	"strconv"
@@ -15,31 +16,36 @@ import (
 
 // CatFileBatch opens git cat-file --batch in the provided repo and returns a stdin pipe, a stdout reader and cancel function
 func CatFileBatch(repoPath string) (*io.PipeWriter, *bufio.Reader, func()) {
-	// Next feed the commits in order into cat-file --batch, followed by their trees and sub trees as necessary.
+	// We often want to feed the commits in order into cat-file --batch, followed by their trees and sub trees as necessary.
 	// so let's create a batch stdin and stdout
 	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").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()))
 		} else {
 			_ = batchStdoutWriter.Close()
 			_ = batchStdinReader.Close()
 		}
+		close(closed)
 	}()
 
 	// For simplicities sake we'll us a buffered reader to read from the cat-file --batch
-	batchReader := bufio.NewReader(batchStdoutReader)
+	batchReader := bufio.NewReaderSize(batchStdoutReader, 32*1024)
 
 	return batchStdinWriter, batchReader, cancel
 }