#261: keep line number gutter visible during horizontal scroll - move the horizontal scroll from the .code flex container to the codebody so the pinned gutter stays in view

A 250-char multipart filename was accepted and echoed verbatim in
Content-Disposition. SanitizeFilename already truncates; lower the cap
from 255 to 128 so DB rows and header echoes stay bounded (#248).

internal/store/attachment.go

@@ -26,7 +26,10 @@ type Attachment struct {
 	SizeHuman string `json:"-"` // template-only: human-readable size
 }
 
-const MaxFilenameLen = 255
+// MaxFilenameLen caps stored attachment filenames (bytes) to bound DB
+// rows and Content-Disposition echoes. 128 keeps names readable while
+// stopping filename-bloat abuse; longer names truncate.
+const MaxFilenameLen = 128
 
 // ErrFileTooLarge is returned when an attachment exceeds the per-file cap.
 var ErrFileTooLarge = errors.New("file too large")

internal/store/blob_test.go

@@ -105,4 +105,9 @@ func TestSanitizeFilename(t *testing.T) {
 	if got := SanitizeFilename(long); len(got) != MaxFilenameLen {
 		t.Errorf("long name len = %d want %d", len(got), MaxFilenameLen)
 	}
+	// issue #248: a 250-char multipart filename must truncate to the cap
+	repro := strings.Repeat("b", 246) + ".txt"
+	if got := SanitizeFilename(repro); len(got) != MaxFilenameLen {
+		t.Errorf("repro name len = %d want %d", len(got), MaxFilenameLen)
+	}
 }

internal/web/static/app.css

@@ -299,8 +299,14 @@ html[data-wrap] .float { overflow-x: hidden; }
 .code-head .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }
 .code {
   font-family: var(--font-mono); font-size: var(--code-fs); line-height: var(--code-lh);
-  padding: 14px 0; display: flex; overflow-x: auto;
+  padding: 14px 0; display: flex; overflow-x: hidden;
 }
+/* #261: horizontal scroll must live on the codebody, not the .code flex
+   container — a container-level scroll takes the gutter with it when the
+   user scrolls long lines. The gutter sits OUTSIDE the scroll container and
+   stays visible; the codebody shrinks to the remaining space and scrolls
+   (min-width: 0 lets it shrink below its content width inside the flex row). */
+.code .codebody { flex: 1 1 auto; min-width: 0; overflow-x: auto; }
 /* #167: the gutter must not drive the flex layout — its content width
    (row count × number width) shrinks the code column, which re-wraps lines,
    which grows the gutter: a feedback loop. Pin the gutter with a fixed
@@ -310,7 +316,7 @@ html[data-wrap] .float { overflow-x: hidden; }
 .code .gutter { flex-shrink: 0; }
 /* gutter/code share line metrics; the editor gutter keeps its own padding (#50) */
 .code .gutter { padding-top: 0; padding-bottom: 0; }
-.codebody { padding: 0 18px; white-space: pre; }
+.codebody { padding: 0 18px; white-space: pre; overflow-x: auto; }
 /* #167: each logical line is its own block so offsetTop identifies its first visual row */
 .codeline { display: block; }
 /* #167 rev: gutter number spans must stack one per visual row (wrap on) */

internal/web/templates/paste.html

@@ -50,7 +50,7 @@
     </div>
   </div>
   {{end}}
-  {{if not .AttachmentImage}}
+  {{if not .Attachment}}
   <div class="float">
     <div class="code" id="code"><div class="gutter" id="gutter">{{.Gutter}}</div><div class="codebody" id="codebody">{{.ContentHTML}}</div></div>
   </div>