(en/decode_coding_object): Fix `after-change-functions`

For `en/decode-coding-string/region`, `after-change-functions`
were either not run at all, or run only after deleting the text
but not after inserting it.

* src/coding.c (decode_coding_object, encode_coding_object): Run the
after-change-functions after inserting the result.

* test/src/editfns-tests.el (sanity-check-change-functions-with-op):
New macro.
(sanity-check-change-functions-errors): New function.
(editfns-tests--before/after-change-functions): Use them to add
cases for `en/decode-coding-string/region`.

1 files changed, 39 insertions, 8 deletions

diff --git a/src/coding.c b/src/coding.c
index c51ceb95475..b21f2ecf00a 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -8109,7 +8109,7 @@ decode_coding_object (struct coding_system *coding,
       set_buffer_internal (XBUFFER (src_object));
       if (from != GPT)
         move_gap_both (from, from_byte);
-      if (EQ (src_object, dst_object))
+      if (BASE_EQ (src_object, dst_object))
         {
           struct Lisp_Marker *tail;
 
@@ -8121,8 +8121,9 @@ decode_coding_object (struct coding_system *coding,
             }
           saved_pt = PT, saved_pt_byte = PT_BYTE;
           TEMP_SET_PT_BOTH (from, from_byte);
-          current_buffer->text->inhibit_shrinking = 1;
-          del_range_both (from, from_byte, to, to_byte, 1);
+          current_buffer->text->inhibit_shrinking = true;
+          prepare_to_modify_buffer (from, to, NULL);
+          del_range_2 (from, from_byte, to, to_byte, false);
           coding->src_pos = -chars;
           coding->src_pos_byte = -bytes;
         }
@@ -8148,6 +8149,13 @@ decode_coding_object (struct coding_system *coding,
     }
   else if (BUFFERP (dst_object))
     {
+      if (!BASE_EQ (src_object, dst_object))
+        {
+          struct buffer *current = current_buffer;
+          set_buffer_internal (XBUFFER (dst_object));
+          prepare_to_modify_buffer (PT, PT, NULL);
+          set_buffer_internal (current);
+        }
       code_conversion_save (0, 0);
       coding->dst_object = dst_object;
       coding->dst_pos = BUF_PT (XBUFFER (dst_object));
@@ -8168,7 +8176,14 @@ decode_coding_object (struct coding_system *coding,
   decode_coding (coding);
 
   if (BUFFERP (coding->dst_object))
-    set_buffer_internal (XBUFFER (coding->dst_object));
+    {
+      set_buffer_internal (XBUFFER (coding->dst_object));
+      signal_after_change (coding->dst_pos,
+                           BASE_EQ (src_object, dst_object) ? to - from : 0,
+                           coding->produced_char);
+      update_compositions (coding->dst_pos,
+                           coding->dst_pos + coding->produced_char, CHECK_ALL);
+    }
 
   if (! NILP (CODING_ATTR_POST_READ (attrs)))
     {
@@ -8373,7 +8388,12 @@ encode_coding_object (struct coding_system *coding,
       if (same_buffer)
         {
           saved_pt = PT, saved_pt_byte = PT_BYTE;
-          coding->src_object = del_range_1 (from, to, 1, 1);
+          /* Run 'prepare_to_modify_buffer' by hand because we don't want
+             to run the after-change hooks yet.  */
+          prepare_to_modify_buffer (from, to, &from);
+          coding->src_object = del_range_2 (from, CHAR_TO_BYTE (from),
+                                            to, CHAR_TO_BYTE (to),
+                                            true);
           coding->src_pos = 0;
           coding->src_pos_byte = 0;
         }
@@ -8404,11 +8424,12 @@ encode_coding_object (struct coding_system *coding,
         {
           struct buffer *current = current_buffer;
 
-          set_buffer_temp (XBUFFER (dst_object));
+          set_buffer_internal (XBUFFER (dst_object));
+          prepare_to_modify_buffer (PT, PT, NULL);
           coding->dst_pos = PT;
           coding->dst_pos_byte = PT_BYTE;
           move_gap_both (coding->dst_pos, coding->dst_pos_byte);
-          set_buffer_temp (current);
+          set_buffer_internal (current);
         }
       coding->dst_multibyte
         = ! NILP (BVAR (XBUFFER (dst_object), enable_multibyte_characters));
@@ -8446,6 +8467,16 @@ encode_coding_object (struct coding_system *coding,
           xfree (coding->destination);
         }
     }
+  else if (BUFFERP (coding->dst_object))
+    {
+      struct buffer *current = current_buffer;
+      set_buffer_internal (XBUFFER (dst_object));
+      signal_after_change (coding->dst_pos, same_buffer ? to - from : 0,
+                           coding->produced_char);
+      update_compositions (coding->dst_pos,
+                           coding->dst_pos + coding->produced_char, CHECK_ALL);
+      set_buffer_internal (current);
+    }
 
   if (saved_pt >= 0)
     {
@@ -9510,7 +9541,7 @@ not fully specified.)  */)
 
 DEFUN ("encode-coding-region", Fencode_coding_region, Sencode_coding_region,
        3, 4, "r\nzCoding system: ",
-       doc: /* Encode the current region using th specified coding system.
+       doc: /* Encode the current region using the specified coding system.
 Interactively, prompt for the coding system to encode the region, and
 replace the region with the bytes that are the result of the encoding.