test: add chmod exit code assertions and missing-file negative test

Co-Authored-By: Claude <noreply@anthropic.com>

src/shell/shell.zig

@@ -2704,6 +2704,11 @@ pub fn NewLexer(comptime encoding: StringEncoding) type {
                             comptime for ('0'..'9') |c| assertSpecialChar(c);
 
                             if (self.chars.state != .Normal) break :escaped;
+                            // Only try to parse a fd redirect (e.g. `2>`) when the digit
+                            // is NOT part of a word already being accumulated.
+                            // Otherwise `./script1<file` would incorrectly strip the
+                            // trailing `1` from the command name. (GH-12602)
+                            if (self.word_start != self.j) break :escaped;
                             const snapshot = self.make_snapshot();
                             if (self.eat_redirect(input)) |redirect| {
                                 try self.break_word(true);

test/regression/issue/12602.test.ts

@@ -0,0 +1,52 @@
+import { $ } from "bun";
+import { expect, test } from "bun:test";
+import { isWindows, tempDir } from "harness";
+
+// GH-12602: Shell incorrectly strips trailing digits from command names
+// when followed by a redirect operator. e.g. `./script1<file` was parsed
+// as `./script` with `1<file` (fd redirect), instead of `./script1` with
+// `<file` (stdin redirect).
+test.skipIf(isWindows)("command name ending in digit followed by redirect is not treated as fd redirect", async () => {
+  using dir = tempDir("12602", {
+    "script1": "#!/bin/sh\necho Hello from script1",
+    "input.txt": "some input",
+  });
+
+  // Make script1 executable
+  const chmodRes = await $`chmod +x ${dir}/script1`.quiet();
+  expect(chmodRes.exitCode).toBe(0);
+
+  // ./script1<input.txt — the "1" must stay part of the command name
+  const result = await $`cd ${dir} && ./script1<input.txt`.quiet();
+  expect(result.text()).toBe("Hello from script1\n");
+  expect(result.exitCode).toBe(0);
+
+  // Redirect from a missing file should fail (the command name must still be correct)
+  const bad = await $`cd ${dir} && ./script1<missing.txt`.quiet().nothrow();
+  expect(bad.exitCode).not.toBe(0);
+});
+
+test.skipIf(isWindows)("command name ending in '2' followed by redirect is not treated as fd redirect", async () => {
+  using dir = tempDir("12602-2", {
+    "script2": "#!/bin/sh\necho Hello from script2",
+    "input.txt": "some input",
+  });
+
+  const chmodRes = await $`chmod +x ${dir}/script2`.quiet();
+  expect(chmodRes.exitCode).toBe(0);
+
+  const result = await $`cd ${dir} && ./script2<input.txt`.quiet();
+  expect(result.text()).toBe("Hello from script2\n");
+  expect(result.exitCode).toBe(0);
+});
+
+test.skipIf(isWindows)("standalone digit redirect still works", async () => {
+  using dir = tempDir("12602-fd", {
+    "input.txt": "hello from file",
+  });
+
+  // `cat 0<input.txt` — 0 is NOT part of a word, so it should be treated as fd redirect
+  const result = await $`cd ${dir} && cat 0<input.txt`.quiet();
+  expect(result.text()).toBe("hello from file");
+  expect(result.exitCode).toBe(0);
+});