(insert_from_buffer_1): Properly count the size

of output from conversion to multibyte even when input
is split across the gap.

1 files changed, 35 insertions, 10 deletions

diff --git a/src/insdel.c b/src/insdel.c
index ab7927964de..31fbae441df 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1388,7 +1388,7 @@ insert_from_buffer_1 (buf, from, nchars, inherit)
      int inherit;
 {
   register Lisp_Object temp;
-  int chunk;
+  int chunk, chunk_expanded;
   int from_byte = buf_charpos_to_bytepos (buf, from);
   int to_byte = buf_charpos_to_bytepos (buf, from + nchars);
   int incoming_nbytes = to_byte - from_byte;
@@ -1403,10 +1403,31 @@ insert_from_buffer_1 (buf, from, nchars, inherit)
   if (NILP (current_buffer->enable_multibyte_characters))
     outgoing_nbytes = nchars;
   else if (NILP (buf->enable_multibyte_characters))
-    outgoing_nbytes
-      = count_size_as_multibyte (BUF_BYTE_ADDRESS (buf, from_byte),
-                                 incoming_nbytes);
+    {
+      int outgoing_before_gap = 0;
+      int outgoing_after_gap = 0;
+
+      if (from < BUF_GPT (buf))
+        {
+          chunk =  BUF_GPT_BYTE (buf) - from_byte;
+          if (chunk > incoming_nbytes)
+            chunk = incoming_nbytes;
+          outgoing_before_gap
+            = count_size_as_multibyte (BUF_BYTE_ADDRESS (buf, from_byte),
+                                       chunk);
+        }
+      else
+        chunk = 0;
+
+      if (chunk < incoming_nbytes)
+        outgoing_after_gap
+          = count_size_as_multibyte (BUF_BYTE_ADDRESS (buf, 
+                                                       from_byte + chunk),
+                                     incoming_nbytes - chunk);
 
+      outgoing_nbytes = outgoing_before_gap + outgoing_after_gap;
+    }
+  
   /* Make sure point-max won't overflow after this insertion.  */
   XSETINT (temp, outgoing_nbytes + Z);
   if (outgoing_nbytes + Z != XINT (temp))
@@ -1427,16 +1448,20 @@ insert_from_buffer_1 (buf, from, nchars, inherit)
       chunk = BUF_GPT_BYTE (buf) - from_byte;
       if (chunk > incoming_nbytes)
         chunk = incoming_nbytes;
-      copy_text (BUF_BYTE_ADDRESS (buf, from_byte),
-                 GPT_ADDR, chunk,
-                 ! NILP (buf->enable_multibyte_characters),
-                 ! NILP (current_buffer->enable_multibyte_characters));
+      /* Record number of output bytes, so we know where
+         to put the output from the second copy_text.  */
+      chunk_expanded
+        = copy_text (BUF_BYTE_ADDRESS (buf, from_byte),
+                     GPT_ADDR, chunk,
+                     ! NILP (buf->enable_multibyte_characters),
+                     ! NILP (current_buffer->enable_multibyte_characters));
     }
   else
-    chunk = 0;
+    chunk_expanded = chunk = 0;
+
   if (chunk < incoming_nbytes)
     copy_text (BUF_BYTE_ADDRESS (buf, from_byte + chunk),
-               GPT_ADDR + chunk, incoming_nbytes - chunk,
+               GPT_ADDR + chunk_expanded, incoming_nbytes - chunk,
                ! NILP (buf->enable_multibyte_characters),
                ! NILP (current_buffer->enable_multibyte_characters));