Fix quarto create producing read-only files from system packages

When Quarto is installed via system packages (e.g. .deb, Nix), resource
files may be read-only. Files copied from these resources by
`quarto create` inherit the read-only permissions, preventing users
from editing them.

Add ensureUserWritable() to src/deno_ral/fs.ts (alongside the
safeModeFromFile/safeChmodSync it depends on) and call it after every
file copy in artifact-shared.ts and project-create.ts.

Author: cderv

news/changelog-1.10.md

@@ -1,3 +1,7 @@
 All changes included in 1.10:
 
+## Commands
 
+### `quarto create`
+
+- ([#14250](https://github.com/quarto-dev/quarto-cli/issues/14250)): Fix `quarto create` producing read-only files when Quarto is installed via system packages (e.g., `.deb`). Files copied from installed resources now have user-write permission ensured.

src/command/create/artifacts/artifact-shared.ts

@@ -12,7 +12,11 @@ import { gfmAutoIdentifier } from "../../../core/pandoc/pandoc-id.ts";
 import { coerce } from "semver/mod.ts";
 import { info } from "../../../deno_ral/log.ts";
 import { basename, dirname, join, relative } from "../../../deno_ral/path.ts";
-import { ensureDirSync, walkSync } from "../../../deno_ral/fs.ts";
+import {
+  ensureDirSync,
+  ensureUserWritable,
+  walkSync,
+} from "../../../deno_ral/fs.ts";
 import { renderEjs } from "../../../core/ejs.ts";
 import { safeExistsSync } from "../../../core/path.ts";
 import { CreateDirective, CreateDirectiveData } from "../cmd-types.ts";
@@ -116,6 +120,7 @@ const renderArtifact = (
     }
     ensureDirSync(dirname(target));
     Deno.copyFileSync(src, target);
+    ensureUserWritable(target);
     return target;
   }
 };

src/deno_ral/fs.ts

@@ -191,3 +191,15 @@ export function safeChmodSync(path: string, mode: number): void {
     }
   }
 }
+
+/**
+ * Ensure a file has user write permission. Files copied from installed
+ * resources (e.g. system packages) may be read-only, but users expect
+ * to edit files created by `quarto create`. No-op on Windows.
+ */
+export function ensureUserWritable(path: string): void {
+  const mode = safeModeFromFile(path);
+  if (mode !== undefined && !(mode & 0o200)) {
+    safeChmodSync(path, mode | 0o200);
+  }
+}

src/project/project-create.ts

@@ -5,7 +5,11 @@
  */
 
 import * as ld from "../core/lodash.ts";
-import { ensureDirSync, existsSync } from "../deno_ral/fs.ts";
+import {
+  ensureDirSync,
+  ensureUserWritable,
+  existsSync,
+} from "../deno_ral/fs.ts";
 import { basename, dirname, join } from "../deno_ral/path.ts";
 import { info } from "../deno_ral/log.ts";
 
@@ -139,6 +143,7 @@ export async function projectCreate(options: ProjectCreateOptions) {
       if (!existsSync(dest)) {
         ensureDirSync(dirname(dest));
         copyTo(src, dest);
+        ensureUserWritable(dest);
         if (!options.quiet) {
           info("- Created " + displayName, { indent: 2 });
         }
@@ -256,6 +261,7 @@ function projectMarkdownFile(
       const name = basename(from);
       const target = join(dirname(path), name);
       copyTo(from, target);
+      ensureUserWritable(target);
     });
 
     return subdirectory ? join(subdirectory, name) : name;