Support loading dynamic docstrings from Emacs <29

* src/doc.c (get_doc_string): Take absolute value to be compatible with
bytecode from Emacs <29.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/doc.c b/src/doc.c
index 0ce1274fe12..6f4ce79f1f1 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -127,7 +127,10 @@ get_doc_string (Lisp_Object filepos, bool unibyte)
   else
     return Qnil;
 
-  EMACS_INT position = XFIXNUM (pos);
+  /* We used to emit negative positions for 'user variables' (whose doc
+     strings started with an asterisk); take the absolute value for
+     compatibility with bytecode from Emacs <29.  */
+  EMACS_INT position = eabs (XFIXNUM (pos));
 
   if (!STRINGP (dir))
     return Qnil;