Do not pdump user-defined hashtabs

* src/pdumper.c (dump_hash_table_stable_p):
Signal an error if a hash table has user-defined tests (Bug#36769).
* src/fns.c (hashfn_user_defined): Now extern.

3 files changed, 4 insertions, 1 deletions

diff --git a/src/fns.c b/src/fns.c
index 8eefa7c72b2..734a2e253c7 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -4017,7 +4017,7 @@ hashfn_eql (Lisp_Object key, struct Lisp_Hash_Table *h)
 /* Given HT, return a hash code for KEY which uses a user-defined
    function to compare keys.  */
 
-static Lisp_Object
+Lisp_Object
 hashfn_user_defined (Lisp_Object key, struct Lisp_Hash_Table *h)
 {
   Lisp_Object args[] = { h->test.user_hash_function, key };
diff --git a/src/lisp.h b/src/lisp.h
index 9d37629bc46..e96fcfe94d3 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3606,6 +3606,7 @@ EMACS_UINT hash_string (char const *, ptrdiff_t);
 EMACS_UINT sxhash (Lisp_Object, int);
 Lisp_Object hashfn_eql (Lisp_Object, struct Lisp_Hash_Table *);
 Lisp_Object hashfn_equal (Lisp_Object, struct Lisp_Hash_Table *);
+Lisp_Object hashfn_user_defined (Lisp_Object, struct Lisp_Hash_Table *);
 Lisp_Object make_hash_table (struct hash_table_test, EMACS_INT, float, float,
                              Lisp_Object, bool);
 ptrdiff_t hash_lookup (struct Lisp_Hash_Table *, Lisp_Object, Lisp_Object *);
diff --git a/src/pdumper.c b/src/pdumper.c
index 2abac80a372..cda8b40be4c 100644
--- a/src/pdumper.c
+++ b/src/pdumper.c
@@ -2628,6 +2628,8 @@ dump_vectorlike_generic (struct dump_context *ctx,
 static bool
 dump_hash_table_stable_p (const struct Lisp_Hash_Table *hash)
 {
+  if (hash->test.hashfn == hashfn_user_defined)
+    error ("cannot dump hash tables with user-defined tests");  /* Bug#36769 */
   bool is_eql = hash->test.hashfn == hashfn_eql;
   bool is_equal = hash->test.hashfn == hashfn_equal;
   ptrdiff_t size = HASH_TABLE_SIZE (hash);