From e4f2f46b93ceca409dafb3e06a32c5ffd945f932 Mon Sep 17 00:00:00 2001
From: awalsh128 <awalsh128@gmail.com>
Date: Sun, 8 Nov 2026 15:17:32 -0800
Subject: [PATCH] fix: find install scripts for package names with regex
 metacharacters

findInstallScript built a regex from the raw package name, so names like
g++ or libstdc++6 threw "Nothing to repeat" on cache save and on restore
with install scripts, and a '.' in a name could match another package's
script. Compare file names as plain strings instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/packages.ts       |  9 +++++++--
 test/packages.test.ts | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/src/packages.ts b/src/packages.ts
index d197d2f..ff52e5e 100644
--- a/src/packages.ts
+++ b/src/packages.ts
@@ -66,10 +66,15 @@ export async function findInstallScript(
     return undefined;
   }
 
-  const pattern = new RegExp(`^${packageName.name}(:.*)?\\.${extension}$`);
+  // Match on plain strings since package names can hold regex metacharacters
+  // (e.g. g++, libstdc++6). Scripts are named <name>[:<arch>].<extension>.
+  const suffix = `.${extension}`;
+  const isMatch = (entry: string) =>
+    entry === `${packageName.name}${suffix}` ||
+    (entry.startsWith(`${packageName.name}:`) && entry.endsWith(suffix));
   const matches = fs
     .readdirSync(scriptsDir)
-    .filter((entry) => pattern.test(entry))
+    .filter(isMatch)
     .sort((a, b) => a.localeCompare(b));
   const candidate = matches[0];
   if (!candidate) {
diff --git a/test/packages.test.ts b/test/packages.test.ts
index f7bde72..859646f 100644
--- a/test/packages.test.ts
+++ b/test/packages.test.ts
@@ -98,6 +98,38 @@ describe("packages", () => {
     expect(result).toBe(path.join(scriptsDir, "test-package.preinst"));
   });
 
+  it.each([
+    ["g++", "g++.postinst"],
+    ["libstdc++6", "libstdc++6:amd64.postinst"],
+  ])(
+    "findInstallScript name %s with regex metacharacters returns its script",
+    async (name, scriptFilename) => {
+      const root = makeTempRoot("pkg-metachar-");
+      const scriptsDir = ensureScriptsDir(root);
+      fs.writeFileSync(path.join(scriptsDir, scriptFilename), "", "utf8");
+
+      const result = await findInstallScript(
+        createPackageName(name),
+        "postinst",
+        root,
+      );
+      expect(result).toBe(path.join(scriptsDir, scriptFilename));
+    },
+  );
+
+  it("findInstallScript name with dot does not match a similarly named package", async () => {
+    const root = makeTempRoot("pkg-dot-");
+    const scriptsDir = ensureScriptsDir(root);
+    fs.writeFileSync(path.join(scriptsDir, "libaXb.postinst"), "", "utf8");
+
+    const result = await findInstallScript(
+      createPackageName("liba.b"),
+      "postinst",
+      root,
+    );
+    expect(result).toBeUndefined();
+  });
+
   it("updateAptLists calls the package manager's update method", async () => {
     const aptListsPath = makeTempRoot("apt-lists-");