patch 8.2.3348: line2byte() returns wrong value after adding textprop

Problem:    line2byte() returns wrong value after adding textprop. (Yuto
            Kimura)
Solution:   Reduce the length by the size of the text property. (closes #8759)

Author: brammool

src/memline.c

@@ -3977,6 +3977,9 @@ ml_flush_line(buf_T *buf)
 	     */
 	    if ((int)dp->db_free >= extra)
 	    {
+#ifdef FEAT_BYTEOFF
+		int old_prop_len = 0;
+#endif
 		// if the length changes and there are following lines
 		count = buf->b_ml.ml_locked_high - buf->b_ml.ml_locked_low + 1;
 		if (extra != 0 && idx < count - 1)
@@ -3995,13 +3998,24 @@ ml_flush_line(buf_T *buf)
 		// adjust free space
 		dp->db_free -= extra;
 		dp->db_txt_start -= extra;
+#ifdef FEAT_BYTEOFF
+		if (buf->b_has_textprop)
+		    old_prop_len = old_len - STRLEN(new_line) - 1;
+#endif
 
 		// copy new line into the data block
 		mch_memmove(old_line - extra, new_line, (size_t)new_len);
 		buf->b_ml.ml_flags |= (ML_LOCKED_DIRTY | ML_LOCKED_POS);
 #ifdef FEAT_BYTEOFF
 		// The else case is already covered by the insert and delete
-		ml_updatechunk(buf, lnum, (long)extra, ML_CHNK_UPDLINE);
+		if (buf->b_has_textprop)
+		{
+		    // Do not count the size of any text properties.
+		    extra += old_prop_len;
+		    extra -= new_len - STRLEN(new_line) - 1;
+		}
+		if (extra != 0)
+		    ml_updatechunk(buf, lnum, (long)extra, ML_CHNK_UPDLINE);
 #endif
 	    }
 	    else
@@ -5595,7 +5609,7 @@ ml_updatechunk(
 		else
 #endif
 		{
-		    if (idx == 0)// first line in block, text at the end
+		    if (idx == 0) // first line in block, text at the end
 			text_end = dp->db_txt_end;
 		    else
 			text_end = ((dp->db_index[idx - 1]) & DB_INDEX_MASK);
@@ -5734,7 +5748,7 @@ ml_find_line_or_offset(buf_T *buf, linenr_T lnum, long *offp)
 	return 1;   // Not a "find offset" and offset 0 _must_ be in line 1
     /*
      * Find the last chunk before the one containing our line. Last chunk is
-     * special because it will never qualify
+     * special because it will never qualify.
      */
     curline = 1;
     curix = size = 0;

src/testdir/test_textprop.vim

@@ -809,8 +809,18 @@ func Test_prop_line2byte()
   call assert_equal(19, line2byte(3))
   call prop_add(1, 1, {'end_col': 3, 'type': 'comment'})
   call assert_equal(19, line2byte(3))
+  bwipe!
 
+  new
+  call setline(1, range(500))
+  call assert_equal(1491, line2byte(401))
+  call prop_add(2, 1, {'type': 'comment'})
+  call prop_add(222, 1, {'type': 'comment'})
+  call assert_equal(1491, line2byte(401))
+  call prop_remove({'type': 'comment'})
+  call assert_equal(1491, line2byte(401))
   bwipe!
+
   call prop_type_delete('comment')
 endfunc
 

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3348,
 /**/
     3347,
 /**/