Update trymerge

.github/scripts/trymerge.py

@@ -20,7 +20,18 @@
 from dataclasses import dataclass
 from functools import lru_cache
 from pathlib import Path
-from typing import Any, Callable, cast, Dict, List, NamedTuple, Optional, Pattern, Tuple
+from typing import (
+    Any,
+    Callable,
+    cast,
+    Dict,
+    Iterable,
+    List,
+    NamedTuple,
+    Optional,
+    Pattern,
+    Tuple,
+)
 from warnings import warn
 
 import yaml
@@ -615,11 +626,11 @@ def can_skip_internal_checks(pr: "GitHubPR", comment_id: Optional[int] = None) -
 def _revlist_to_prs(
     repo: GitRepo,
     pr: "GitHubPR",
-    rev_list: List[str],
+    rev_list: Iterable[str],
     should_skip: Optional[Callable[[int, "GitHubPR"], bool]] = None,
 ) -> List[Tuple["GitHubPR", str]]:
     rc: List[Tuple[GitHubPR, str]] = []
-    for idx, rev in enumerate(reversed(rev_list)):
+    for idx, rev in enumerate(rev_list):
         msg = repo.commit_message(rev)
         m = RE_PULL_REQUEST_RESOLVED.search(msg)
         if m is None:
@@ -658,7 +669,7 @@ def skip_func(idx: int, candidate: "GitHubPR") -> bool:
         return True
 
     assert pr.is_ghstack_pr()
-    entire_stack = _revlist_to_prs(repo, pr, rev_list, skip_func)
+    entire_stack = _revlist_to_prs(repo, pr, reversed(rev_list), skip_func)
 
     for stacked_pr, rev in entire_stack:
         if stacked_pr.is_closed():
@@ -1790,22 +1801,38 @@ def validate_revert(
 
 
 def get_ghstack_dependent_prs(
-    repo: GitRepo, pr: GitHubPR
+    repo: GitRepo, pr: GitHubPR, only_closed: bool = True
 ) -> List[Tuple[str, GitHubPR]]:
+    """
+    Get the PRs in the stack that are above this PR (inclusive).
+    Throws error if stack have branched or original branches are gone
+    """
     assert pr.is_ghstack_pr()
     orig_ref = f"{repo.remote}/{pr.get_ghstack_orig_ref()}"
     rev_list = repo.revlist(f"{pr.default_branch()}..{orig_ref}")
+    if len(rev_list) == 0:
+        raise RuntimeError(
+            f"PR {pr.pr_num} does not have any revisions associated with it"
+        )
+    skip_len = len(rev_list) - 1
     for branch in repo.branches_containing_ref(orig_ref):
         candidate = repo.revlist(f"{pr.default_branch()}..{branch}")
         # Pick longest candidate
         if len(candidate) > len(rev_list):
             candidate, rev_list = rev_list, candidate
         # Validate that candidate always ends rev-list
         if rev_list[-len(candidate) :] != candidate:
-            raise RuntimeError("Ieee...")
+            raise RuntimeError(
+                f"Branch {branch} revlist {', '.join(candidate)} is not a subset of {', '.join(rev_list)}"
+            )
+    # Remove commits original PR depends on
+    if skip_len > 0:
+        rev_list = rev_list[:-skip_len]
     rc: List[Tuple[str, GitHubPR]] = []
     for pr_, sha in _revlist_to_prs(repo, pr, rev_list):
         if not pr_.is_closed():
+            if not only_closed:
+                rc.append(("", pr_))
             continue
         commit_sha = get_pr_commit_sha(repo, pr_)
         rc.append((commit_sha, pr_))
@@ -1876,11 +1903,17 @@ def try_revert(
         if comment_id is not None
         else "\n"
     )
-    shas_and_prs = (
-        get_ghstack_dependent_prs(repo, pr)
-        if pr.is_ghstack_pr()
-        else [(commit_sha, pr)]
-    )
+    shas_and_prs = [(commit_sha, pr)]
+    if pr.is_ghstack_pr():
+        try:
+            shas_and_prs = get_ghstack_dependent_prs(repo, pr)
+            prs_to_revert = " ".join([t[1].get_pr_url() for t in shas_and_prs])
+            print(f"About to stack of PRs: {prs_to_revert}")
+        except Exception as e:
+            print(
+                f"Failed to fetch dependent PRs: {str(e)}, fall over to single revert"
+            )
+
     do_revert_prs(
         repo,
         shas_and_prs,