--- hgext/convert/__init__.py.orig	2020-08-03 17:43:51 UTC
+++ hgext/convert/__init__.py
@@ -59,6 +59,13 @@ testedwith = b'ships-with-hg-core'
         ),
         (
             b'',
+            b'authormapsuffix',
+            b'',
+            _(b'append this suffix to remapped author names'),
+            _(b'SUFFIX')
+        ),
+        (
+            b'',
             b'filemap',
             b'',
             _(b'remap file names using contents of file'),
--- hgext/convert/convcmd.py.orig	2020-08-03 17:43:51 UTC
+++ hgext/convert/convcmd.py
@@ -74,7 +74,7 @@ def readauthormap(ui, authorfile, author
                 continue
 
             srcauthor = srcauthor.strip()
-            dstauthor = dstauthor.strip()
+            dstauthor = dstauthor.strip() + self.authormapsuffix
             if authors.get(srcauthor) in (None, dstauthor):
                 msg = _(b'mapping author %s to %s\n')
                 ui.debug(msg % (srcauthor, dstauthor))
@@ -209,12 +209,16 @@ class converter(object):
         self.commitcache = {}
         self.authors = {}
         self.authorfile = None
+        self.authormapsuffix = b''
 
         # Record converted revisions persistently: maps source revision
         # ID to target revision ID (both strings).  (This is how
         # incremental conversions work.)
         self.map = mapfile(ui, revmapfile)
 
+        if opts.get('authormapsuffix'):
+            self.authormapsuffix = opts.get('authormapsuffix')
+
         # Read first the dst author map if any
         authorfile = self.dest.authorfile()
         if authorfile and os.path.exists(authorfile):
@@ -482,7 +486,7 @@ class converter(object):
 
     def cachecommit(self, rev):
         commit = self.source.getcommit(rev)
-        commit.author = self.authors.get(commit.author, commit.author)
+        commit.author = self.authors.get(commit.author, commit.author + self.authormapsuffix)
         commit.branch = mapbranch(commit.branch, self.branchmap)
         self.commitcache[rev] = commit
         return commit