mugit @ a00560c

M internal/git/gitservice/gitservice.go

@@ -5,11 +5,9 @@ "bytes"
 	"fmt"
 	"io"
 	"os/exec"
-	"strings"
+	"sync"
 	"syscall"
 )
-
-// Thanks https://git.icyphox.sh/legit/blob/master/git/service/service.go
 
 // InfoRefs executes git-upload-pack --advertise-refs for smart-HTTP discovery.
 func InfoRefs(dir string, out io.Writer) error {
@@ -20,9 +18,12 @@ "--advertise-refs",
 		".")
 	cmd.Dir = dir
 	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
-	stdoutPipe, _ := cmd.StdoutPipe()
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("stdout pipe: %w", err)
+	}
 	cmd.Stderr = cmd.Stdout
-	defer stdoutPipe.Close()
 
 	if err := cmd.Start(); err != nil {
 		return fmt.Errorf("start git-upload-pack: %w", err)
@@ -31,20 +32,17 @@
 	if err := packLine(out, "# service=git-upload-pack\n"); err != nil {
 		return fmt.Errorf("write pack line: %w", err)
 	}
-
 	if err := packFlush(out); err != nil {
 		return fmt.Errorf("flush pack: %w", err)
 	}
 
 	var buf bytes.Buffer
-	if _, err := io.Copy(&buf, stdoutPipe); err != nil {
+	if _, err := io.Copy(&buf, stdout); err != nil {
 		return fmt.Errorf("copy stdout to buffer: %w", err)
 	}
 
 	if err := cmd.Wait(); err != nil {
-		var out strings.Builder
-		io.Copy(&out, &buf)
-		return fmt.Errorf("git-upload-pack: %w: %s", err, out.String())
+		return fmt.Errorf("git-upload-pack: %w", err)
 	}
 
 	if _, err := io.Copy(out, &buf); err != nil {
@@ -55,42 +53,99 @@ return nil
 }
 
 // UploadPack executes git-upload-pack for smart-HTTP git fetch/clone.
-func UploadPack(dir string, in io.Reader, out io.Writer) error {
-	cmd := exec.Command("git",
-		"-c", "uploadpack.allowFilter=true",
-		"upload-pack",
-		"--stateless-rpc",
-		".")
-	cmd.Dir = dir
+// StatelessRPC should be true in case it's used over http, and false for ssh.
+func UploadPack(dir string, statelessRPC bool, in io.Reader, out io.Writer) error {
+	return gitCmd("upload-pack", config{
+		Dir:          dir,
+		StatelessRPC: statelessRPC,
+		AllowFilter:  true,
+		Stdin:        in,
+		Stdout:       out,
+	})
+}
+
+func ReceivePack(dir string, in io.Reader, out io.Writer) error {
+	return gitCmd("receive-pack", config{
+		Dir:    dir,
+		Stdin:  in,
+		Stdout: out,
+	})
+}
+
+type config struct {
+	Dir          string
+	StatelessRPC bool
+	AllowFilter  bool
+	ExtraArgs    []string
+	Stdin        io.Reader
+	Stdout       io.Writer
+}
+
+func gitCmd(service string, c config) error {
+	args := []string{}
+	if c.AllowFilter {
+		args = append(args, "-c", "uploadpack.allowFilter=true")
+	}
+
+	args = append(args, service)
+	if c.StatelessRPC {
+		args = append(args, "--stateless-rpc")
+	}
+
+	args = append(args, c.ExtraArgs...)
+	args = append(args, ".")
+
+	cmd := exec.Command("git", args...)
+	cmd.Dir = c.Dir
 	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 
-	stdoutPipe, _ := cmd.StdoutPipe()
-	cmd.Stderr = cmd.Stdout
-	defer stdoutPipe.Close()
+	var (
+		err   error
+		stdin io.WriteCloser
+	)
+
+	if c.Stdin != nil {
+		stdin, err = cmd.StdinPipe()
+		if err != nil {
+			return err
+		}
+	}
 
-	stdinPipe, err := cmd.StdinPipe()
+	stdout, err := cmd.StdoutPipe()
 	if err != nil {
-		return fmt.Errorf("stdin pipe: %w", err)
+		return err
 	}
-	defer stdinPipe.Close()
+	cmd.Stderr = cmd.Stdout
 
 	if err := cmd.Start(); err != nil {
-		return fmt.Errorf("start git-upload-pack: %w", err)
+		return fmt.Errorf("start %s: %w", service, err)
 	}
 
-	if _, err := io.Copy(stdinPipe, in); err != nil {
-		return fmt.Errorf("copy to stdin: %w", err)
+	if c.Stdin != nil {
+		// Don't add to WaitGroup - stdin closes when client closes,
+		// shouldn't block waiting for output to finish
+		go func() {
+			defer stdin.Close()
+			io.Copy(stdin, c.Stdin)
+		}()
 	}
-	stdinPipe.Close()
+
+	var wg sync.WaitGroup
+	var stdoutErr error
+
+	wg.Go(func() {
+		_, stdoutErr = io.Copy(c.Stdout, stdout)
+	})
 
-	if _, err := io.Copy(out, stdoutPipe); err != nil {
-		return fmt.Errorf("copy stdout: %w", err)
+	wg.Wait()
+
+	if stdoutErr != nil {
+		return fmt.Errorf("copy stdout: %w", stdoutErr)
 	}
 
 	if err := cmd.Wait(); err != nil {
-		return fmt.Errorf("git-upload-pack: %w", err)
+		return fmt.Errorf("%s: %w", service, err)
 	}
-
 	return nil
 }
 

M internal/handlers/git.go

@@ -20,7 +20,6 @@ w.WriteHeader(http.StatusOK)
 
 	if err := gitservice.InfoRefs(
 		filepath.Join(h.c.Repo.Dir, name), // FIXME: use securejoin
-		true,
 		w,
 	); err != nil {
 		slog.Error("git: info/refs", "err", err)