fix: ensure clones support --filter

Justfile

@@ -29,7 +29,7 @@ lint:
 fmt:
     just --unstable --fmt
     git ls-files | grep '\.go$' | xargs gosimports -local github.com/block -w
-    go fmt ./...
+    git ls-files | grep '\.go$' | xargs dirname | uniq | sed 's,^,./,' | xargs go fmt
     go mod tidy
 
 # ============================================================================
@@ -61,10 +61,9 @@ build-all:
 # Run
 # ============================================================================
 
-# Run natively
-run: build
-    @echo "→ Starting cachew at http://localhost:8080"
-    proctor
+# Run dev server with hot reload
+dev:
+    @proctor
 
 # Clean up build artifacts
 clean:

Procfile

@@ -1 +1 @@
-cachewd **/*.go !**/*_test.go debounce=2s ready=http:8080/_readiness=200: CACHEW_URL=http://localhost:8080 CACHEW_LOG_LEVEL=debug cachewd
+cachewd **/*.go !**/*_test.go !state/**/* debounce=2s ready=http:8080/_readiness=200: CACHEW_URL=http://localhost:8080 CACHEW_LOG_LEVEL=debug cachewd

bin/proctor

@@ -1 +1 @@
-.proctor-0.5.0.pkg
+.proctor-0.8.0.pkg

cachew.hcl

@@ -23,8 +23,8 @@ metrics {}
 
 
 git {
-  bundle-interval = "24h"
-  snapshot-interval = "24h"
+  #bundle-interval = "24h"
+  #snapshot-interval = "24h"
 }
 
 host "https://w3.org" {}

internal/gitclone/manager.go

@@ -365,6 +365,13 @@ func (r *Repository) executeClone(ctx context.Context) error {
 		return errors.Wrapf(err, "fetch all branches: %s", string(output))
 	}
 
+	// Enable partial clone support (e.g. --filter=blob:none) when serving via git http-backend.
+	cmd = exec.CommandContext(ctx, "git", "-C", r.path, "config", "uploadpack.allowFilter", "true") // #nosec G204
+	output, err = cmd.CombinedOutput()
+	if err != nil {
+		return errors.Wrapf(err, "configure uploadpack.allowFilter: %s", string(output))
+	}
+
 	return nil
 }
 

internal/gitclone/manager_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 
@@ -279,6 +280,46 @@ func TestRepository_Clone_StateVisibleDuringClone(t *testing.T) {
 	assert.Equal(t, StateReady, repo.State())
 }
 
+func TestRepository_CloneSetsAllowFilter(t *testing.T) {
+	ctx := context.Background()
+	tmpDir := t.TempDir()
+
+	upstreamPath := filepath.Join(tmpDir, "upstream.git")
+	workPath := filepath.Join(tmpDir, "work")
+	assert.NoError(t, os.MkdirAll(workPath, 0o755))
+
+	cmd := exec.Command("git", "-C", workPath, "init")
+	assert.NoError(t, cmd.Run())
+	cmd = exec.Command("git", "-C", workPath, "config", "user.email", "test@example.com")
+	assert.NoError(t, cmd.Run())
+	cmd = exec.Command("git", "-C", workPath, "config", "user.name", "Test")
+	assert.NoError(t, cmd.Run())
+	assert.NoError(t, os.WriteFile(filepath.Join(workPath, "f.txt"), []byte("x"), 0o644))
+	cmd = exec.Command("git", "-C", workPath, "add", ".")
+	assert.NoError(t, cmd.Run())
+	cmd = exec.Command("git", "-C", workPath, "commit", "-m", "init")
+	assert.NoError(t, cmd.Run())
+	cmd = exec.Command("git", "clone", "--bare", workPath, upstreamPath)
+	assert.NoError(t, cmd.Run())
+
+	clonePath := filepath.Join(tmpDir, "clone")
+	repo := &Repository{
+		state:       StateEmpty,
+		path:        clonePath,
+		upstreamURL: upstreamPath,
+		fetchSem:    make(chan struct{}, 1),
+	}
+	repo.fetchSem <- struct{}{}
+
+	assert.NoError(t, repo.Clone(ctx))
+	assert.Equal(t, StateReady, repo.State())
+
+	cmd = exec.Command("git", "-C", clonePath, "config", "uploadpack.allowFilter")
+	output, err := cmd.Output()
+	assert.NoError(t, err)
+	assert.Equal(t, "true", strings.TrimSpace(string(output)))
+}
+
 func TestRepository_HasCommit(t *testing.T) {
 	ctx := context.Background()
 	tmpDir := t.TempDir()

internal/strategy/git/backend.go

@@ -3,6 +3,7 @@ package git
 import (
 	"bytes"
 	"context"
+	"io"
 	"log/slog"
 	"net/http"
 	"net/http/cgi" //nolint:gosec // CVE-2016-5386 only affects Go < 1.6.3
@@ -67,13 +68,27 @@ func (s *Strategy) serveFromBackend(w http.ResponseWriter, r *http.Request, repo
 			Env: []string{
 				"GIT_PROJECT_ROOT=" + absRoot,
 				"GIT_HTTP_EXPORT_ALL=1",
+				"GIT_HTTP_MAX_REQUEST_BUFFER=100M",
 				"PATH=" + os.Getenv("PATH"),
 			},
 		}
 
 		r2 := r.Clone(r.Context())
 		r2.URL.Path = backendPath
 
+		// Go's cgi.Handler rejects chunked request bodies with a 400.
+		// Buffer the body so we can set ContentLength and clear TransferEncoding.
+		if r2.ContentLength < 0 {
+			body, err := io.ReadAll(r2.Body)
+			if err != nil {
+				httputil.ErrorResponse(w, r, http.StatusInternalServerError, "failed to read request body")
+				return errors.Wrap(err, "read request body")
+			}
+			r2.Body = io.NopCloser(bytes.NewReader(body))
+			r2.ContentLength = int64(len(body))
+			r2.TransferEncoding = nil
+		}
+
 		handler.ServeHTTP(w, r2)
 
 		if stderrBuf.Len() > 0 {