fix(shared): keep quoted Git file names intact

packages/shared/src/gitPatchPath.test.ts

@@ -35,6 +35,7 @@ describe("a name written into a header and read back out", () => {
     "with space.txt",
     "café/résumé.ts",
     "🚀.ts",
+    "\uFEFFtab\tfile.txt",
     "tab\tfile.txt",
     "line\nfile.txt",
     "carriage\rfile.txt",
@@ -66,6 +67,13 @@ describe("a name written into a header and read back out", () => {
 });
 
 describe("unquoteGitPatchPath", () => {
+  it.each(['"\\357\\273\\277note.txt"', "\\357\\273\\277note.txt"])(
+    "preserves an escaped U+FEFF at the start of a filename: %j",
+    (token) => {
+      expect(unquoteGitPatchPath(token)).toBe("\uFEFFnote.txt");
+    },
+  );
+
   it("leaves a token git saw no need to quote alone", () => {
     expect(unquoteGitPatchPath("src/app.ts")).toBe("src/app.ts");
     expect(unquoteGitPatchPath("with space.txt")).toBe("with space.txt");

packages/shared/src/gitPatchPath.ts

@@ -43,7 +43,8 @@ const LOWEST_PRINTABLE = 0x20;
 const BACKSLASH = 0x5c;
 
 const utf8 = new TextEncoder();
-const fromUtf8 = new TextDecoder();
+// A leading U+FEFF is part of the filename, not an encoding marker.
+const fromUtf8 = new TextDecoder("utf-8", { ignoreBOM: true });
 
 /**
  * A name as a patch header can carry it: itself where that is unambiguous, and git's quoted form

packages/source-control-core/src/server/diffFileRevisions.test.ts

@@ -72,6 +72,20 @@ describe("parseDiffFileRevisions", () => {
     assert.deepStrictEqual([...revisions], [["new.ts", "2222222"]]);
   });
 
+  it("keeps a leading U+FEFF in a quoted rename's revision key", () => {
+    const revisions = parseDiffFileRevisions(
+      patchOf(
+        'diff --git a/old.txt "b/\\357\\273\\277note.txt"',
+        "similarity index 100%",
+        "rename from old.txt",
+        'rename to "\\357\\273\\277note.txt"',
+        "index 2222222..2222222 100644",
+      ),
+    );
+
+    assert.deepStrictEqual([...revisions], [["\uFEFFnote.txt", "2222222"]]);
+  });
+
   it("leaves out a file Bitbucket excluded, which it gives no index line for", () => {
     const revisions = parseDiffFileRevisions(
       patchOf(