(code_convert_region): Handle the case that codes

0240..0377 are generated just after a multibyte character.

1 files changed, 44 insertions, 2 deletions

diff --git a/src/coding.c b/src/coding.c
index 2c1364d540d..bf5677b8a43 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -4238,8 +4238,50 @@ code_convert_region (from, from_byte, to, to_byte, coding, encodep, adjust)
     }
   if (src - dst > 0) *dst = 0; /* Put an anchor.  */
 
-  if (multibyte && (fake_multibyte || !encodep && (to - from) != (to_byte - from_byte)))
-    inserted = multibyte_chars_in_text (GPT_ADDR, inserted_byte);
+  if (multibyte)
+    {
+      if (fake_multibyte || !encodep && (to - from) != (to_byte - from_byte))
+        inserted = multibyte_chars_in_text (GPT_ADDR, inserted_byte);
+
+      if (! CHAR_HEAD_P (*GPT_ADDR)
+          && GPT_BYTE > 1
+          && from_byte == from_byte_orig)
+        {
+          unsigned char *p0 = GPT_ADDR - 1, *pmin = BEG_ADDR, *p1, *pmax;
+
+          while (! CHAR_HEAD_P (*p0) && p0 > pmin) p0--;
+          if (BASE_LEADING_CODE_P (*p0))
+            {
+              /* Codes in the range 0240..0377 were inserted after a
+                 multibyte sequence.  We must treat those codes as
+                 tailing constituents of the multibyte sequence.  For
+                 that, we increase byte positions of position keepers
+                 whose char positions are GPT.  */
+              int byte_increase;
+              p1 = GPT_ADDR + 2, pmax = p0 + 1 + inserted_byte;
+              Lisp_Object tail;
+
+              while (! CHAR_HEAD_P (*p1) && p1 < pmax) p1++;
+              /* Now, codes from P0 to P1 constitute a single
+                 multibyte character.  */
+
+              byte_increase = p1 - GPT_ADDR;
+              if (PT == GPT)
+                current_buffer->pt_byte += byte_increase;
+              tail = BUF_MARKERS (current_buffer);
+              while (XSYMBOL (tail) != XSYMBOL (Qnil))
+                {
+                  if (XMARKER (tail)->charpos == GPT)
+                    XMARKER (tail)->bytepos += byte_increase;
+                  tail = XMARKER (tail)->chain;
+                }
+
+              from_byte += byte_increase;
+              from_byte_orig = from_byte;
+              inserted -= byte_increase;
+            }
+        }
+    }
 
   /* Update various buffer positions for the new text.  */
   GAP_SIZE -= inserted_byte;