# HG changeset patch
# User Martin von Zweigbergk <martinvonz@google.com>
# Date 1602800196 25200
# Node ID 4a38b12141b5a94e4492ddeed507f008196f995c
# Parent  edb026c44f61b614f13adf2102a2e15261de8726
evolvecmd: extract function for rewriting hashes in commit message

The logic for rewriting hashes is somewhat long and well isolated, so
a function makes good sense.

diff -r edb026c44f61 -r 4a38b12141b5 hgext3rd/evolve/evolvecmd.py
--- a/hgext3rd/evolve/evolvecmd.py	Tue Feb 09 19:11:39 2021 +0800
+++ b/hgext3rd/evolve/evolvecmd.py	Thu Oct 15 15:16:36 2020 -0700
@@ -896,6 +896,42 @@
     ordering.extend(sorted(dependencies))
     return ordering
 
+def _rewrite_commit_message_hashes(repo, commitmsg):
+    """filter a commit description to update has to their successors
+
+    The goal of this function is to avoid description referencing obsolete
+    hashes when a stack is rewritten or evolved.
+
+    Each hash in the description will be detected and, if matching an obsolete
+    changeset, it will be replaced by its successors.
+
+
+    Note: They might be case were such behavior might be is wrong, for example
+    if the commit message is explicitely referencing an older, obsolete changesets.
+    """
+    cache = {}
+    sha1s = re.findall(sha1re, commitmsg)
+    unfi = repo.unfiltered()
+    for sha1 in sha1s:
+        fullnode = scmutil.resolvehexnodeidprefix(unfi, sha1)
+        if fullnode is None:
+            continue
+        ctx = unfi[fullnode]
+        if not ctx.obsolete():
+            continue
+
+        successors = obsutil.successorssets(repo, ctx.node(), cache=cache)
+
+        # We can't make any assumptions about how to update the hash if the
+        # cset in question was split or diverged.
+        if len(successors) == 1 and len(successors[0]) == 1:
+            newsha1 = nodemod.hex(successors[0][0])
+            commitmsg = commitmsg.replace(sha1, newsha1[:len(sha1)])
+        else:
+            repo.ui.note(_(b'The stale commit message reference to %s could '
+                           b'not be updated\n') % sha1)
+    return commitmsg
+
 def _relocate(repo, orig, dest, evolvestate, pctx=None, keepbranch=False,
               category=None):
     """rewrites the orig rev on dest rev
@@ -917,29 +953,7 @@
             raise error.ProgrammingError(msg, hint)
         pctx = orig.p1()
 
-    commitmsg = orig.description()
-
-    cache = {}
-    sha1s = re.findall(sha1re, commitmsg)
-    unfi = repo.unfiltered()
-    for sha1 in sha1s:
-        fullnode = scmutil.resolvehexnodeidprefix(unfi, sha1)
-        if fullnode is None:
-            continue
-        ctx = unfi[fullnode]
-        if not ctx.obsolete():
-            continue
-
-        successors = obsutil.successorssets(repo, ctx.node(), cache=cache)
-
-        # We can't make any assumptions about how to update the hash if the
-        # cset in question was split or diverged.
-        if len(successors) == 1 and len(successors[0]) == 1:
-            newsha1 = nodemod.hex(successors[0][0])
-            commitmsg = commitmsg.replace(sha1, newsha1[:len(sha1)])
-        else:
-            repo.ui.note(_(b'The stale commit message reference to %s could '
-                           b'not be updated\n') % sha1)
+    commitmsg = _rewrite_commit_message_hashes(repo, orig.description())
 
     tr = repo.currenttransaction()
     assert tr is not None