(decode_coding): Avoid nested *-change-functions (bug#78042)

* src/coding.c (decode_coding): Avoid nested *-change-functions (bug#78042).

* test/src/editfns-tests.el (sanity-check-change-functions-before)
(sanity-check-change-functions-after): Record notifications in
`sanity-check-change-functions-op`.
(sanity-check-change-functions-with-op): Don't rely on
`sanity-check-change-functions-op` always holding only the `op`.
(sanity-check-change-functions-errors): Include the sequence of
notifications in the error info.
(editfns-tests--before/after-change-functions): Add tests for (bug#78042).

1 files changed, 5 insertions, 1 deletions

diff --git a/src/coding.c b/src/coding.c
index 63b0dbeb18b..a923b6bd82d 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -7363,6 +7363,7 @@ decode_coding (struct coding_system *coding)
   struct ccl_spec cclspec;
   int carryover;
   int i;
+  specpdl_ref count = SPECPDL_INDEX ();
 
   USE_SAFE_ALLOCA;
 
@@ -7389,6 +7390,9 @@ decode_coding (struct coding_system *coding)
 
       undo_list = BVAR (current_buffer, undo_list);
       bset_undo_list (current_buffer, Qt);
+      /* Avoid running nested *-change-functions via 'produce_annotation'.
+         Our callers run *-change-functions over the whole region anyway.  */
+      specbind (Qinhibit_modification_hooks, Qt);
     }
 
   coding->consumed = coding->consumed_char = 0;
@@ -7501,7 +7505,7 @@ decode_coding (struct coding_system *coding)
       record_insert (coding->dst_pos, coding->produced_char);
     }
 
-  SAFE_FREE ();
+  SAFE_FREE_UNBIND_TO (count, Qnil);
 }