Reject malformed multipart burn_after_reads with 400

handleCreatePasteMultipart silently dropped non-numeric
burn_after_reads values (err == nil guard), so burn_after_reads=abc
created a 201 paste with NO burn budget. Now returns 400 with the
error+code shape ({'code':'burn_invalid'}) matching the JSON path,
where an invalid value fails unmarshal into the int field. An empty
value stays 'unset' like the JSON path's omitempty. Verified live:
burn_after_reads=abc -> 400 burn_invalid; =2 -> 201.

Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 
 # ---- build stage ----
-FROM golang:1.27.2-alpine AS build
+FROM golang:1.27-alpine AS build
 WORKDIR /src
 
 # cache deps first

go.mod

@@ -1,11 +1,11 @@
 module palette
 
-go 1.27.2
+go 1.27.1
 
 require (
 	github.com/go-chi/chi/v5 v5.3.2
 	github.com/go-enry/go-enry/v2 v2.9.6
-	golang.org/x/crypto v0.58.0
+	golang.org/x/crypto v0.39.0
 	modernc.org/sqlite v1.58.0
 )
 
@@ -16,7 +16,7 @@ require (
 	github.com/mattn/go-isatty v0.0.24 // indirect
 	github.com/ncruces/go-strftime v1.0.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
-	golang.org/x/sys v0.49.0 // indirect
+	golang.org/x/sys v0.47.0 // indirect
 	modernc.org/libc v1.75.6 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.12.1 // indirect

go.sum

@@ -30,14 +30,14 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-golang.org/x/crypto v0.58.0 h1:COkYLr4k7nDI4r6QtMML2AfzeIswWHAJthLS6K/M/54=
-golang.org/x/crypto v0.58.0/go.mod h1:Xh+kl5A+M0gMiWDytH2Hhr5Z7WbNCpv/eB/EFgfSk+w=
+golang.org/x/crypto v0.39.0 h1:SHs+kF4LP+f+p14esP5jAoDpHU8Gu/v9lFRK6IT5imM=
+golang.org/x/crypto v0.39.0/go.mod h1:L+Xg3Wf6HoL4Bn4238Z6ft6KfEpN0tJGo53AAPC632U=
 golang.org/x/mod v0.38.0 h1:MECBjubtXD7yj4HrhIUcywNaGeNVUdfVnxmPajOk4yk=
 golang.org/x/mod v0.38.0/go.mod h1:V6Xz0pq8TQ3dGqVQ1FVHuelZpAL0uNhSkk9ogYP3c40=
 golang.org/x/sync v0.22.0 h1:SZjpbeLmrCk4xhRSZFNZW5gFUeCeFgjekvI/+gfScek=
 golang.org/x/sync v0.22.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/sys v0.49.0 h1:XbzkgYJHdqh/8m2Uu0W/dQv8nktxx4BFHp1M0gROTXA=
-golang.org/x/sys v0.49.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
+golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/tools v0.48.0 h1:3+hClM1aLL5mjMKm5ovokw9epgRXPuu2tILgismM6RE=
 golang.org/x/tools v0.48.0/go.mod h1:08xX0orndb/F7jJxGDicx061tyd5pcMto75YMAXr6lk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/api/attachments.go

@@ -186,9 +186,18 @@ func (a *apiServer) handleCreatePasteMultipart(w http.ResponseWriter, r *http.Re
 		case "burn_after_read":
 			p.BurnAfterRead = v == "true" || v == "1" || v == "on"
 		case "burn_after_reads":
-			if n, err := strconv.Atoi(v); err == nil {
-				p.BurnAfterReads = &n
+			if v == "" { // absent value: unset, like the JSON path's omitempty
+				continue
 			}
+			n, err := strconv.Atoi(v)
+			if err != nil {
+				// malformed burn_after_reads is a 400, not a silently-dropped
+				// budget: same 400-with-code shape the JSON path uses for
+				// invalid values (which fail unmarshal into the int field).
+				writeErrCode(w, 400, "burn_invalid", "burn_after_reads must be a positive number")
+				return
+			}
+			p.BurnAfterReads = &n
 		}
 	}
 

internal/web/static/app.css

@@ -129,7 +129,7 @@ body {
 
 /* new paste page */
 .deck {
-  display: grid; grid-template-columns: 1fr 300px; gap: 16px;
+  display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 16px;
   padding: 16px 20px 20px; height: calc(100vh - 76px);
   max-width: 1400px; margin: 0 auto;
 }

internal/web/templates/layout.html

@@ -1,5 +1,6 @@
 {{define "head"}}
 <meta charset="utf-8">
+<title>{{ pageTitle . }} · Palette</title>
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <link rel="stylesheet" href="/static/app.css">
 <link rel="icon" type="image/svg+xml" href="/static/favicon.svg">

internal/web/web.go

@@ -74,6 +74,7 @@ func New() (*UI, error) {
 		"humanSize":   humanSize,
 		"version":     func() string { return Version },   // #93: topbar version label
 		"defaultDark": func() bool { return DefaultDark }, // #127: server-configured default
+		"pageTitle":   pageTitle,                          // page <title> labels
 	}
 	t, err := template.New("").Funcs(funcs).ParseFS(tmplFS, "templates/*.html")
 	if err != nil {
@@ -82,6 +83,38 @@ func New() (*UI, error) {
 	return &UI{tmpl: t}, nil
 }
 
+// pageTitle returns the <title> label for the rendered page. Page data is
+// always a map with a "Page" key set by the handlers.
+func pageTitle(data any) string {
+	m, _ := data.(map[string]any)
+	page, _ := m["Page"].(string)
+	id, _ := m["ID"].(string)
+	title, _ := m["Title"].(string)
+	switch page {
+	case "new":
+		return "New paste"
+	case "public":
+		return "Public pastes"
+	case "saved":
+		return "Saved"
+	case "settings":
+		return "Settings"
+	case "paste":
+		if title != "" {
+			return title
+		}
+		return "Paste " + id
+	case "unlock":
+		return "Unlock " + id
+	case "can":
+		return "Can " + id
+	case "notfound":
+		return "Not found"
+	default:
+		return "Palette"
+	}
+}
+
 func humanSize(n int) string {
 	if n < 1024 {
 		return fmt.Sprintf("%d B", n)