Commit `ddab521653`

ddab52165310177c117b89a07d5b155e56fb56dc

parent: 0a4bb99d63

Verified · cmc ci/build: success ci/test: success ci/vuln: success

cmc <hello@cleberg.net> · 2026-09-04 01:39 UTC

web: a diff cut at 4 MiB says so, and the commit list says how many it hides

Diff and ShowPatch cut the patch at the byte limit mid-line and
reported nothing, so the last hunk rendered wrong and the diffstat
under-reported. Both now cut on a line boundary and return whether
they did; the commit and merge request pages show a notice and the
diffstat says its counts are partial; mr diff and repo commit say so
on stderr. The merge request's commit list is capped at 100 and now
says "first 100 of N".

Closes #117

Layout: unified · split

internal/control/mr.go +4 −1

		@@ -548,11 +548,14 @@ func runMRDiff(c *Ctx, args []string) int {
548	548	}
549	549	base = b
550	550	}
551		patch, err := gitutil.Diff(dir, base, head, 4<<20)
	551	patch, truncated, err := gitutil.Diff(dir, base, head, 4<<20)
552	552	if err != nil {
553	553	return c.fail(protocol.ExitFailure, "%v", err)
554	554	}
555	555	fmt.Fprint(c.Stdout, patch)
	556	if truncated {
	557	fmt.Fprintln(c.Stderr, "diff truncated at 4 MiB; fetch the branch for the rest")
	558	}
556	559	return protocol.ExitOK
557	560	}
558	561

internal/control/sig.go +4 −1

		@@ -246,10 +246,13 @@ func runRepoCommit(c *Ctx, args []string) int {
246	246	if err != nil {
247	247	return c.fail(protocol.ExitFailure, "verifying %s: %v", full, err)
248	248	}
249		patch, err := gitutil.ShowPatch(dir, full, 4<<20)
	249	patch, truncated, err := gitutil.ShowPatch(dir, full, 4<<20)
250	250	if err != nil {
251	251	return c.fail(protocol.ExitFailure, "%v", err)
252	252	}
	253	if truncated {
	254	fmt.Fprintln(c.Stderr, "patch truncated at 4 MiB; clone the repository for the rest")
	255	}
253	256	statuses, err := c.Store.ListCommitStatuses(repo.ID, full)
254	257	if err != nil {
255	258	return c.fail(protocol.ExitFailure, "%v", err)

internal/gitutil/endofoptions_test.go +1 −1

		@@ -35,7 +35,7 @@ func TestRefsAreNotOptions(t *testing.T) {
35	35	"Archive": func() error { return Archive(dir, ref, "x", &sink) },
36	36	"Grep": func() error { _, err := Grep(dir, ref, "hi", 10); return err },
37	37	"MergeBase": func() error { _, err := MergeBase(dir, ref, "main"); return err },
38		"Diff": func() error { _, err := Diff(dir, ref, "main", 1<<20); return err },
	38	"Diff": func() error { _, _, err := Diff(dir, ref, "main", 1<<20); return err },
39	39	"DiffFiles": func() error { _, err := DiffFiles(dir, ref, "main"); return err },
40	40	"RevListRange": func() error { _, err := RevListRange(dir, "main", ref); return err },
41	41	"Blame": func() error { _, err := Blame(dir, ref, "f.txt", 1, 1); return err },

internal/gitutil/merge.go +20 −6

		@@ -1,6 +1,7 @@
1	1	package gitutil
2	2
3	3	import (
	4	"bytes"
4	5	"fmt"
5	6	"os"
6	7	"os/exec"
		@@ -93,17 +94,30 @@ func CommitTree(dir, tree string, parents []string, name, email, message string)
93	94	}
94	95
95	96	// Diff returns the patch for old..new (three-dot semantics are the caller's
96		// job: pass the merge base as old).
97		func Diff(dir, old, new string, limit int64) (string, error) {
	97	// job: pass the merge base as old), cut at limit bytes on a line boundary;
	98	// truncated says whether it was cut, so the caller can say so instead of
	99	// rendering a hunk that ends mid-line (#117).
	100	func Diff(dir, old, new string, limit int64) (patch string, truncated bool, err error) {
98	101	cmd := exec.Command("git", "-C", dir, "diff", "--stat", "--patch", "--end-of-options", old, new)
99	102	out, err := cmd.Output()
100	103	if err != nil {
101		return "", fmt.Errorf("diff: %w", err)
	104	return "", false, fmt.Errorf("diff: %w", err)
102	105	}
103		if int64(len(out)) > limit {
104		out = out[:limit]
	106	out, truncated = cutAtLine(out, limit)
	107	return string(out), truncated, nil
	108	}
	109
	110	// cutAtLine keeps at most limit bytes, ending on the last newline before
	111	// the limit.
	112	func cutAtLine(out []byte, limit int64) ([]byte, bool) {
	113	if int64(len(out)) <= limit {
	114	return out, false
	115	}
	116	cut := out[:limit]
	117	if i := bytes.LastIndexByte(cut, '\n'); i >= 0 {
	118	cut = cut[:i+1]
105	119	}
106		return string(out), nil
	120	return cut, true
107	121	}
108	122
109	123	// MergeBase returns the best common ancestor, or an error if none exists.

internal/gitutil/read.go +9 −7

		@@ -151,21 +151,23 @@ func (c *cappedWriter) Write(p []byte) (int, error) {
151	151	}
152	152
153	153	// ShowPatch returns the stat+patch text for one commit.
154		func ShowPatch(dir, sha string, limit int64) (string, error) {
155		cmd := exec.Command("git", "-C", dir, "show", "--stat", "--patch", "--format=", sha)
	154	func ShowPatch(dir, sha string, limit int64) (patch string, truncated bool, err error) {
	155	cmd := exec.Command("git", "-C", dir, "show", "--stat", "--patch", "--format=", "--end-of-options", sha)
156	156	stdout, err := cmd.StdoutPipe()
157	157	if err != nil {
158		return "", err
	158	return "", false, err
159	159	}
160	160	if err := cmd.Start(); err != nil {
161		return "", err
	161	return "", false, err
162	162	}
163		data, _ := io.ReadAll(io.LimitReader(stdout, limit))
	163	// One byte past the limit says whether there was more.
	164	data, _ := io.ReadAll(io.LimitReader(stdout, limit+1))
164	165	io.Copy(io.Discard, stdout)
165	166	if err := cmd.Wait(); err != nil {
166		return "", fmt.Errorf("show %s: %w", sha, err)
	167	return "", false, fmt.Errorf("show %s: %w", sha, err)
167	168	}
168		return string(data), nil
	169	data, truncated = cutAtLine(data, limit)
	170	return string(data), truncated, nil
169	171	}
170	172
171	173	// IsBinary reports whether data looks like binary content.

internal/httpd/web.go +11 −5

		@@ -1448,7 +1448,7 @@ func (s Server) commit(w http.ResponseWriter, r http.Request) {
1448	1448	s.notFound(w, r)
1449	1449	return
1450	1450	}
1451		patch, _ := gitutil.ShowPatch(p.Dir, full, 4<<20)
	1451	patch, truncated, _ := gitutil.ShowPatch(p.Dir, full, 4<<20)
1452	1452	files := parseDiff(patch)
1453	1453	committerEmail := ""
1454	1454	if parsed.CommitterEmail != parsed.AuthorEmail {
		@@ -1468,9 +1468,10 @@ func (s Server) commit(w http.ResponseWriter, r http.Request) {
1468	1468	Sig sigView
1469	1469	Checks []store.CommitStatus
1470	1470	DiffFiles []diffFile
	1471	DiffTruncated bool
1471	1472	}{p, full, full[:10], commitNames.name(parsed.AuthorEmail, parsed.AuthorName), parsed.AuthorEmail, commitUser, committerEmail,
1472	1473	time.Unix(parsed.AuthorUnix, 0).UTC().Format(time.RFC3339), msg,
1473		gitutil.Parents(p.Dir, full), v, checks, files})
	1474	gitutil.Parents(p.Dir, full), v, checks, files, truncated})
1474	1475	}
1475	1476
1476	1477	// labelPalette provides default label chip colors: mid-tone hues that stay
		@@ -1661,9 +1662,10 @@ func (s Server) mr(w http.ResponseWriter, r http.Request) {
1661	1662	base = b
1662	1663	}
1663	1664	}
	1665	var diffTruncated bool
1664	1666	if base != "" {
1665		if patch, err := gitutil.Diff(p.Dir, base, headRef, 4<<20); err == nil {
1666		files = parseDiff(patch)
	1667	if patch, truncated, err := gitutil.Diff(p.Dir, base, headRef, 4<<20); err == nil {
	1668	files, diffTruncated = parseDiff(patch), truncated
1667	1669	}
1668	1670	}
1669	1671	md := s.ugcFor(r, p.Repo)
		@@ -1682,9 +1684,11 @@ func (s Server) mr(w http.ResponseWriter, r http.Request) {
1682	1684	}
1683	1685	mrNames := s.authorNames()
1684	1686	var commits []commitRow
	1687	commitsTotal := 0
1685	1688	if base != "" {
1686	1689	const maxMRCommits = 100
1687	1690	shas, _ := gitutil.RevListRange(p.Dir, base, headRef)
	1691	commitsTotal = len(shas)
1688	1692	if len(shas) > maxMRCommits {
1689	1693	shas = shas[:maxMRCommits]
1690	1694	}
		@@ -1730,8 +1734,10 @@ func (s Server) mr(w http.ResponseWriter, r http.Request) {
1730	1734	Comments []renderedComment
1731	1735	Reviews []store.MRReview
1732	1736	DiffFiles []diffFile
	1737	DiffTruncated bool
1733	1738	Stat diffStat
1734	1739	Commits []commitRow
	1740	CommitsTotal int
1735	1741	Branches []gitutil.Ref
1736	1742	CanEdit bool
1737	1743	CanWrite bool
		@@ -1741,7 +1747,7 @@ func (s Server) mr(w http.ResponseWriter, r http.Request) {
1741	1747	StackedOn *store.MR
1742	1748	Stacked []store.MR
1743	1749	}{p, m, view, md(m.Body, m.BodyFormat), checks, combined, renderComments(comments, md),
1744		reviews, files, stat, commits, branches, s.canEditItem(r, p.Repo, m.Author),
	1750	reviews, files, diffTruncated, stat, commits, commitsTotal, branches, s.canEditItem(r, p.Repo, m.Author),
1745	1751	canWrite, unresolved, r.URL.Query().Get("e"), detachedThreads, stackedOn, stacked})
1746	1752	}
1747	1753

internal/web/templates/commit.html +1

		@@ -9,5 +9,6 @@
9	9	{{if .CommitterEmail}}<br>committer: <{{.CommitterEmail}}>{{end}}</p>
10	10	</div>
11	11	<pre class="message">{{.Message}}</pre>
	12	{{if .DiffTruncated}}<p class="error" role="alert">This patch is larger than 4 MiB and is cut off below. Clone the repository to see all of it.</p>{{end}}
12	13	{{template "difffiles" dict "Files" .DiffFiles "Base" "" "Viewer" ""}}
13	14	{{end}}

internal/web/templates/mr.html +3 −1

		@@ -57,6 +57,7 @@
57	57	{{end}}
58	58
59	59	{{else if eq .View "commits"}}
	60	{{if gt .CommitsTotal (len .Commits)}}<p class="meta">first {{len .Commits}} of {{.CommitsTotal}} commits; the rest are in the branch</p>{{end}}
60	61	<ul class="loglist">
61	62	{{range .Commits}}<li>
62	63	<div class="commitmain">
		@@ -73,7 +74,8 @@
73	74	</ul>
74	75
75	76	{{else}}
76		<p class="diffstat">{{.Stat.Files}} file{{if ne .Stat.Files 1}}s{{end}} changed, <span class="add">+{{.Stat.Adds}}</span> <span class="del">−{{.Stat.Dels}}</span></p>
	77	<p class="diffstat">{{.Stat.Files}} file{{if ne .Stat.Files 1}}s{{end}} changed, <span class="add">+{{.Stat.Adds}}</span> <span class="del">−{{.Stat.Dels}}</span>{{if .DiffTruncated}} · shown up to 4 MiB; the counts and the last file are partial{{end}}</p>
	78	{{if .DiffTruncated}}<p class="error" role="alert">This diff is larger than 4 MiB and is cut off below. Fetch the branch to see all of it.</p>{{end}}
77	79	{{template "difffiles" dict "Files" .DiffFiles "Base" $base "Viewer" .Viewer}}
78	80	{{end}}
79	81

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