Merge branch 'master' of github.com:ckelsel/neovim into vim-8.0.0101

21 files changed, 359 insertions, 201 deletions

diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index bbbd5ab2dc..afbee09c1c 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -242,39 +242,7 @@ static void push_call(UI *ui, char *name, Array args)
 static void remote_ui_highlight_set(UI *ui, HlAttrs attrs)
 {
   Array args = ARRAY_DICT_INIT;
-  Dictionary hl = ARRAY_DICT_INIT;
-
-  if (attrs.bold) {
-    PUT(hl, "bold", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.underline) {
-    PUT(hl, "underline", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.undercurl) {
-    PUT(hl, "undercurl", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.italic) {
-    PUT(hl, "italic", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.reverse) {
-    PUT(hl, "reverse", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.foreground != -1) {
-    PUT(hl, "foreground", INTEGER_OBJ(attrs.foreground));
-  }
-
-  if (attrs.background != -1) {
-    PUT(hl, "background", INTEGER_OBJ(attrs.background));
-  }
-
-  if (attrs.special != -1) {
-    PUT(hl, "special", INTEGER_OBJ(attrs.special));
-  }
+  Dictionary hl = hlattrs2dict(attrs);
 
   ADD(args, DICTIONARY_OBJ(hl));
   push_call(ui, "highlight_set", args);
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index ab893a4c0f..98f4410347 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -55,6 +55,47 @@ void nvim_command(String command, Error *err)
   try_end(err);
 }
 
+/// Gets a highlight definition by name.
+///
+/// @param name Highlight group name
+/// @param rgb Export RGB colors
+/// @param[out] err Error details, if any
+/// @return Highlight definition map
+/// @see nvim_get_hl_by_id
+Dictionary nvim_get_hl_by_name(String name, Boolean rgb, Error *err)
+  FUNC_API_SINCE(3)
+{
+  Dictionary result = ARRAY_DICT_INIT;
+  int id = syn_name2id((const char_u *)name.data);
+
+  if (id == 0) {
+    api_set_error(err, kErrorTypeException, "Invalid highlight name: %s",
+                  name.data);
+    return result;
+  }
+  result = nvim_get_hl_by_id(id, rgb, err);
+  return result;
+}
+
+/// Gets a highlight definition by id. |hlID()|
+///
+/// @param hl_id Highlight id as returned by |hlID()|
+/// @param rgb Export RGB colors
+/// @param[out] err Error details, if any
+/// @return Highlight definition map
+/// @see nvim_get_hl_by_name
+Dictionary nvim_get_hl_by_id(Integer hl_id, Boolean rgb, Error *err)
+  FUNC_API_SINCE(3)
+{
+  Dictionary dic = ARRAY_DICT_INIT;
+  if (syn_get_final_id((int)hl_id) == 0) {
+    api_set_error(err, kErrorTypeException, "Invalid highlight id: %d", hl_id);
+    return dic;
+  }
+  int attrcode = syn_id2attr((int)hl_id);
+  return hl_get_attr_by_id(attrcode, rgb, err);
+}
+
 /// Passes input keys to Nvim.
 /// On VimL error: Does not fail, but updates v:errmsg.
 ///
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 724a8578ac..fc5bb90973 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -3069,8 +3069,8 @@ static bool ti_change(char_u *str, char_u **last)
 /// Set current window title
 void resettitle(void)
 {
-  ui_call_set_title(cstr_as_string((char *)lasttitle));
   ui_call_set_icon(cstr_as_string((char *)lasticon));
+  ui_call_set_title(cstr_as_string((char *)lasttitle));
   ui_flush();
 }
 
diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index 403ef65c4f..577fc13a31 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -762,7 +762,7 @@ bool vim_isIDc(int c)
 }
 
 /// Check that "c" is a keyword character:
-/// Letters and characters from 'iskeyword' option for current buffer.
+/// Letters and characters from 'iskeyword' option for the current buffer.
 /// For multi-byte characters mb_get_class() is used (builtin rules).
 ///
 /// @param  c  character to check
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 5ee91d417a..b2a0d9a767 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -6733,6 +6733,39 @@ static void prepare_assert_error(garray_T *gap)
   }
 }
 
+// Append "str" to "gap", escaping unprintable characters.
+// Changes NL to \n, CR to \r, etc.
+static void ga_concat_esc(garray_T *gap, char_u *str)
+{
+  char_u *p;
+  char_u buf[NUMBUFLEN];
+
+  if (str == NULL) {
+    ga_concat(gap, (char_u *)"NULL");
+    return;
+  }
+
+  for (p = str; *p != NUL; p++) {
+    switch (*p) {
+      case BS: ga_concat(gap, (char_u *)"\\b"); break;
+      case ESC: ga_concat(gap, (char_u *)"\\e"); break;
+      case FF: ga_concat(gap, (char_u *)"\\f"); break;
+      case NL: ga_concat(gap, (char_u *)"\\n"); break;
+      case TAB: ga_concat(gap, (char_u *)"\\t"); break;
+      case CAR: ga_concat(gap, (char_u *)"\\r"); break;
+      case '\\': ga_concat(gap, (char_u *)"\\\\"); break;
+      default:
+        if (*p < ' ') {
+          vim_snprintf((char *)buf, NUMBUFLEN, "\\x%02x", *p);
+          ga_concat(gap, buf);
+        } else {
+          ga_append(gap, *p);
+        }
+        break;
+    }
+  }
+}
+
 // Fill "gap" with information about an assert error.
 static void fill_assert_error(garray_T *gap, typval_T *opt_msg_tv,
                               char_u *exp_str, typval_T *exp_tv,
@@ -6753,11 +6786,11 @@ static void fill_assert_error(garray_T *gap, typval_T *opt_msg_tv,
       ga_concat(gap, (char_u *)"Expected ");
     }
     if (exp_str == NULL) {
-      tofree = (char_u *) encode_tv2string(exp_tv, NULL);
-      ga_concat(gap, tofree);
+      tofree = (char_u *)encode_tv2string(exp_tv, NULL);
+      ga_concat_esc(gap, tofree);
       xfree(tofree);
     } else {
-      ga_concat(gap, exp_str);
+      ga_concat_esc(gap, exp_str);
     }
     if (atype != ASSERT_NOTEQUAL) {
       if (atype == ASSERT_MATCH) {
@@ -6768,7 +6801,7 @@ static void fill_assert_error(garray_T *gap, typval_T *opt_msg_tv,
         ga_concat(gap, (char_u *)" but got ");
       }
       tofree = (char_u *)encode_tv2string(got_tv, NULL);
-      ga_concat(gap, tofree);
+      ga_concat_esc(gap, tofree);
       xfree(tofree);
     }
   }
@@ -17495,7 +17528,7 @@ static void f_winsaveview(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   tv_dict_add_nr(dict, S_LEN("skipcol"), (varnumber_T)curwin->w_skipcol);
 }
 
-/// Writes list of strings to file
+/// Write "list" of strings to file "fd".
 ///
 /// @param  fp  File to write to.
 /// @param[in]  list  List to write.
diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index f5949333bd..4f8a8528a0 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -868,20 +868,15 @@ int ins_typebuf(char_u *str, int noremap, int offset, int nottyped, bool silent)
 
   addlen = (int)STRLEN(str);
 
-  /*
-   * Easy case: there is room in front of typebuf.tb_buf[typebuf.tb_off]
-   */
   if (offset == 0 && addlen <= typebuf.tb_off) {
+    // Easy case: there is room in front of typebuf.tb_buf[typebuf.tb_off]
     typebuf.tb_off -= addlen;
     memmove(typebuf.tb_buf + typebuf.tb_off, str, (size_t)addlen);
-  }
-  /*
-   * Need to allocate a new buffer.
-   * In typebuf.tb_buf there must always be room for 3 * MAXMAPLEN + 4
-   * characters.  We add some extra room to avoid having to allocate too
-   * often.
-   */
-  else {
+  } else {
+    // Need to allocate a new buffer.
+    // In typebuf.tb_buf there must always be room for 3 * MAXMAPLEN + 4
+    // characters.  We add some extra room to avoid having to allocate too
+    // often.
     newoff = MAXMAPLEN + 4;
     newlen = typebuf.tb_len + addlen + newoff + 4 * (MAXMAPLEN + 4);
     if (newlen < 0) {               /* string is getting too long */
@@ -1663,10 +1658,10 @@ static int vgetorpeek(int advance)
     }
     if (c != NUL && !got_int) {
       if (advance) {
-        /* KeyTyped = FALSE;  When the command that stuffed something
-         * was typed, behave like the stuffed command was typed.
-         * needed for CTRL-W CTRl-] to open a fold, for example. */
-        KeyStuffed = TRUE;
+        // KeyTyped = FALSE;  When the command that stuffed something
+        // was typed, behave like the stuffed command was typed.
+        // needed for CTRL-W CTRL-] to open a fold, for example.
+        KeyStuffed = true;
       }
       if (typebuf.tb_no_abbr_cnt == 0)
         typebuf.tb_no_abbr_cnt = 1;             /* no abbreviations now */
diff --git a/src/nvim/gettext.h b/src/nvim/gettext.h
index aa0e97233e..60317b8484 100644
--- a/src/nvim/gettext.h
+++ b/src/nvim/gettext.h
@@ -13,6 +13,7 @@
 #else
 # define _(x) ((char *)(x))
 # define N_(x) x
+# define ngettext(x, xs, n) ((n) == 1 ? (x) : (xs))
 # define bindtextdomain(x, y)  // empty
 # define bind_textdomain_codeset(x, y)  // empty
 # define textdomain(x)  // empty
diff --git a/src/nvim/indent_c.c b/src/nvim/indent_c.c
index 4a6393ac36..279d45bb0a 100644
--- a/src/nvim/indent_c.c
+++ b/src/nvim/indent_c.c
@@ -734,16 +734,20 @@ static int cin_ispreproc(char_u *s)
   return FALSE;
 }
 
-/*
- * Return TRUE if line "*pp" at "*lnump" is a preprocessor statement or a
- * continuation line of a preprocessor statement.  Decrease "*lnump" to the
- * start and return the line in "*pp".
- */
-static int cin_ispreproc_cont(char_u **pp, linenr_T *lnump)
+/// Return TRUE if line "*pp" at "*lnump" is a preprocessor statement or a
+/// continuation line of a preprocessor statement.  Decrease "*lnump" to the
+/// start and return the line in "*pp".
+/// Put the amount of indent in "*amount".
+static int cin_ispreproc_cont(char_u **pp, linenr_T *lnump, int *amount)
 {
   char_u      *line = *pp;
   linenr_T lnum = *lnump;
-  int retval = FALSE;
+  int retval = false;
+  int candidate_amount = *amount;
+
+  if (*line != NUL && line[STRLEN(line) - 1] == '\\') {
+    candidate_amount = get_indent_lnum(lnum);
+  }
 
   for (;; ) {
     if (cin_ispreproc(line)) {
@@ -758,8 +762,12 @@ static int cin_ispreproc_cont(char_u **pp, linenr_T *lnump)
       break;
   }
 
-  if (lnum != *lnump)
+  if (lnum != *lnump) {
     *pp = ml_get(*lnump);
+  }
+  if (retval) {
+    *amount = candidate_amount;
+  }
   return retval;
 }
 
@@ -1994,10 +2002,12 @@ int get_c_indent(void)
         amount = -1;
         for (lnum = cur_curpos.lnum - 1; lnum > our_paren_pos.lnum; --lnum) {
           l = skipwhite(ml_get(lnum));
-          if (cin_nocode(l))                    /* skip comment lines */
+          if (cin_nocode(l)) {                   // skip comment lines
             continue;
-          if (cin_ispreproc_cont(&l, &lnum))
-            continue;                           /* ignore #define, #if, etc. */
+          }
+          if (cin_ispreproc_cont(&l, &lnum, &amount)) {
+            continue;                           // ignore #define, #if, etc.
+          }
           curwin->w_cursor.lnum = lnum;
 
           /* Skip a comment or raw string. XXX */
@@ -2353,15 +2363,14 @@ int get_c_indent(void)
            * up with it.
            */
           if (curwin->w_cursor.lnum <= ourscope) {
-            /* we reached end of scope:
-             * if looking for an enum or structure initialization
-             * go further back:
-             * if it is an initializer (enum xxx or xxx =), then
-             * don't add ind_continuation, otherwise it is a variable
-             * declaration:
-             * int x,
-             *     here; <-- add ind_continuation
-             */
+            // We reached end of scope:
+            // If looking for a enum or structure initialization
+            // go further back:
+            // If it is an initializer (enum xxx or xxx =), then
+            // don't add ind_continuation, otherwise it is a variable
+            // declaration:
+            // int x,
+            //     here; <-- add ind_continuation
             if (lookfor == LOOKFOR_ENUM_OR_INIT) {
               if (curwin->w_cursor.lnum == 0
                   || curwin->w_cursor.lnum
@@ -2389,11 +2398,12 @@ int get_c_indent(void)
                 continue;
               }
 
-              /*
-               * Skip preprocessor directives and blank lines.
-               */
-              if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum))
+              //
+              // Skip preprocessor directives and blank lines.
+              //
+              if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum, &amount)) {
                 continue;
+              }
 
               if (cin_nocode(l))
                 continue;
@@ -2497,9 +2507,10 @@ int get_c_indent(void)
                   continue;
                 }
 
-                /* Skip preprocessor directives and blank lines. */
-                if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum))
+                // Skip preprocessor directives and blank lines.
+                if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum, &amount)) {
                   continue;
+                }
 
                 /* Finally the actual check for "namespace". */
                 if (cin_is_cpp_namespace(l)) {
@@ -2662,9 +2673,10 @@ int get_c_indent(void)
            * unlocked it)
            */
           l = get_cursor_line_ptr();
-          if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum)
-              || cin_nocode(l))
+          if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum, &amount)
+              || cin_nocode(l)) {
             continue;
+          }
 
           /*
            * Are we at the start of a cpp base class declaration or
@@ -3309,11 +3321,12 @@ term_again:
       break;
     }
 
-    /*
-     * Skip preprocessor directives and blank lines.
-     */
-    if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum))
+    //
+    // Skip preprocessor directives and blank lines.
+    //
+    if (cin_ispreproc_cont(&l, &curwin->w_cursor.lnum, &amount)) {
       continue;
+    }
 
     if (cin_nocode(l))
       continue;
@@ -3405,9 +3418,10 @@ term_again:
 
       while (curwin->w_cursor.lnum > 1) {
         look = ml_get(--curwin->w_cursor.lnum);
-        if (!(cin_nocode(look) || cin_ispreproc_cont(
-                &look, &curwin->w_cursor.lnum)))
+        if (!(cin_nocode(look)
+              || cin_ispreproc_cont(&look, &curwin->w_cursor.lnum, &amount))) {
           break;
+        }
       }
       if (curwin->w_cursor.lnum > 0
           && cin_ends_in(look, (char_u *)"}", NULL))
diff --git a/src/nvim/main.c b/src/nvim/main.c
index 024c56dd05..ea7a58bda3 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -649,6 +649,11 @@ void getout(int exitval)
   /* Position the cursor again, the autocommands may have moved it */
   ui_cursor_goto((int)Rows - 1, 0);
 
+  // Apply 'titleold'.
+  if (p_title && *p_titleold != NUL) {
+    ui_call_set_title(cstr_as_string((char *)p_titleold));
+  }
+
 #if defined(USE_ICONV) && defined(DYNAMIC_ICONV)
   iconv_end();
 #endif
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 8911f72692..7cecb16686 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -2501,7 +2501,7 @@ return {
       no_mkrc=true,
       vi_def=true,
       varname='p_titleold',
-      defaults={if_true={vi=N_("Thanks for flying Vim")}}
+      defaults={if_true={vi=N_("")}}
     },
     {
       full_name='titlestring',
diff --git a/src/nvim/path.c b/src/nvim/path.c
index f2339c8046..51adcfb135 100644
--- a/src/nvim/path.c
+++ b/src/nvim/path.c
@@ -1690,6 +1690,9 @@ int vim_FullName(const char *fname, char *buf, size_t len, bool force)
 
   if (strlen(fname) > (len - 1)) {
     xstrlcpy(buf, fname, len);  // truncate
+#ifdef WIN32
+    slash_adjust(buf);
+#endif
     return FAIL;
   }
 
@@ -1702,6 +1705,9 @@ int vim_FullName(const char *fname, char *buf, size_t len, bool force)
   if (rv == FAIL) {
     xstrlcpy(buf, fname, len);  // something failed; use the filename
   }
+#ifdef WIN32
+  slash_adjust(buf);
+#endif
   return rv;
 }
 
@@ -2196,11 +2202,11 @@ static int path_get_absolute_path(const char_u *fname, char_u *buf,
 
   // expand it if forced or not an absolute path
   if (force || !path_is_absolute_path(fname)) {
-    if ((p = vim_strrchr(fname, '/')) != NULL) {
+    if ((p = vim_strrchr(fname, PATHSEP)) != NULL) {
       // relative to root
       if (p == fname) {
         // only one path component
-        relative_directory[0] = '/';
+        relative_directory[0] = PATHSEP;
         relative_directory[1] = NUL;
       } else {
         assert(p >= fname);
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 921ef06c7b..5659f30f64 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -2201,16 +2201,17 @@ win_line (
   int change_end = -1;                  /* last col of changed area */
   colnr_T trailcol = MAXCOL;            /* start of trailing spaces */
   int need_showbreak = false;           // overlong line, skip first x chars
-  int line_attr = 0;                    /* attribute for the whole line */
-  matchitem_T *cur;                     /* points to the match list */
-  match_T     *shl;                     /* points to search_hl or a match */
-  int shl_flag;                         /* flag to indicate whether search_hl
-                                           has been processed or not */
-  int prevcol_hl_flag;                  /* flag to indicate whether prevcol
-                                           equals startcol of search_hl or one
-                                           of the matches */
-  int prev_c = 0;                       /* previous Arabic character */
-  int prev_c1 = 0;                      /* first composing char for prev_c */
+  int line_attr = 0;                    // attribute for the whole line
+  int line_attr_low_priority = 0;       // current line, lowest priority
+  matchitem_T *cur;                     // points to the match list
+  match_T     *shl;                     // points to search_hl or a match
+  int shl_flag;                         // flag to indicate whether search_hl
+                                        // has been processed or not
+  int prevcol_hl_flag;                  // flag to indicate whether prevcol
+                                        // equals startcol of search_hl or one
+                                        // of the matches
+  int prev_c = 0;                       // previous Arabic character
+  int prev_c1 = 0;                      // first composing char for prev_c
   int did_line_attr = 0;
 
   bool search_attr_from_match = false;  // if search_attr is from :match
@@ -2427,10 +2428,17 @@ win_line (
     filler_lines = wp->w_topfill;
   filler_todo = filler_lines;
 
-  /* If this line has a sign with line highlighting set line_attr. */
+  // 'cursorline' highlighting for the current window.  Not when Visual mode is
+  // active, because it's not clear what is selected then.
+  if (wp->w_p_cul && lnum == wp->w_cursor.lnum
+      && !(wp == curwin && VIsual_active)) {
+    line_attr_low_priority = win_hl_attr(wp, HLF_CUL);
+  }
+
   v = buf_getsigntype(wp->w_buffer, lnum, SIGN_LINEHL);
-  if (v != 0)
-      line_attr = sign_get_attr((int)v, TRUE);
+  if (v != 0) {
+    line_attr = sign_get_attr((int)v, true);
+  }
 
   // Highlight the current line in the quickfix window.
   if (bt_quickfix(wp->w_buffer) && qf_current_entry(wp) == lnum) {
@@ -2441,7 +2449,7 @@ win_line (
     line_attr = hl_combine_attr(wp->w_hl_attr_normal, line_attr);
   }
 
-  if (line_attr != 0) {
+  if (line_attr_low_priority || line_attr) {
     area_highlighting = true;
   }
 
@@ -2663,20 +2671,6 @@ win_line (
       cur = cur->next;
   }
 
-  /* Cursor line highlighting for 'cursorline' in the current window.  Not
-   * when Visual mode is active, because it's not clear what is selected
-   * then. */
-  if (wp->w_p_cul && lnum == wp->w_cursor.lnum
-      && !(wp == curwin && VIsual_active)) {
-    if (line_attr != 0 && !(State & INSERT) && bt_quickfix(wp->w_buffer)
-        && qf_current_entry(wp) == lnum) {
-      line_attr = hl_combine_attr(win_hl_attr(wp, HLF_CUL), line_attr);
-    } else {
-      line_attr = win_hl_attr(wp, HLF_CUL);
-    }
-    area_highlighting = true;
-  }
-
   off = (unsigned)(current_ScreenLine - ScreenLines);
   col = 0;
   if (wp->w_p_rl) {
@@ -3594,15 +3588,15 @@ win_line (
                    && lcs_eol_one > 0) {
           // Display a '$' after the line or highlight an extra
           // character if the line break is included.
-          // For a diff line the highlighting continues after the
-          // "$".
-          if (diff_hlf == (hlf_T)0 && line_attr == 0) {
-            /* In virtualedit, visual selections may extend
-             * beyond end of line. */
+          // For a diff line the highlighting continues after the "$".
+          if (diff_hlf == (hlf_T)0
+              && line_attr == 0
+              && line_attr_low_priority == 0) {
+            // In virtualedit, visual selections may extend beyond end of line.
             if (area_highlighting && virtual_active()
-                && tocol != MAXCOL && vcol < tocol)
+                && tocol != MAXCOL && vcol < tocol) {
               n_extra = 0;
-            else {
+            } else {
               p_extra = at_end_str;
               n_extra = 1;
               c_extra = NUL;
@@ -3661,7 +3655,7 @@ win_line (
                      (col < wp->w_width))) {
           c = ' ';
           ptr--;  // put it back at the NUL
-        } else if ((diff_hlf != (hlf_T)0 || line_attr != 0)
+        } else if ((diff_hlf != (hlf_T)0 || line_attr_low_priority || line_attr)
                    && (wp->w_p_rl
                        ? (col >= 0)
                        : (col - boguscols < wp->w_width))) {
@@ -3673,7 +3667,8 @@ win_line (
           did_line_attr++;
 
           // don't do search HL for the rest of the line
-          if (line_attr != 0 && char_attr == search_attr && col > 0) {
+          if ((line_attr_low_priority || line_attr)
+              && char_attr == search_attr && col > 0) {
             char_attr = line_attr;
           }
           if (diff_hlf == HLF_TXD) {
@@ -4035,13 +4030,16 @@ win_line (
       if (wp->w_p_cuc && VCOL_HLC == (long)wp->w_virtcol
           && lnum != wp->w_cursor.lnum) {
         vcol_save_attr = char_attr;
-        char_attr = hl_combine_attr(char_attr, win_hl_attr(wp, HLF_CUC));
+        char_attr = hl_combine_attr(win_hl_attr(wp, HLF_CUC), char_attr);
       } else if (draw_color_col && VCOL_HLC == *color_cols) {
         vcol_save_attr = char_attr;
-        char_attr = hl_combine_attr(char_attr, win_hl_attr(wp, HLF_MC));
+        char_attr = hl_combine_attr(win_hl_attr(wp, HLF_MC), char_attr);
       }
     }
 
+    // Apply `line_attr_low_priority` now, so that everthing can override it.
+    char_attr = hl_combine_attr(line_attr_low_priority, char_attr);
+
     /*
      * Store character to be displayed.
      * Skip characters that are left of the screen for 'nowrap'.
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 65c0e2464a..0224b28c2a 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -42,6 +42,7 @@
 #include "nvim/ui.h"
 #include "nvim/os/os.h"
 #include "nvim/os/time.h"
+#include "nvim/api/private/helpers.h"
 
 static bool did_syntax_onoff = false;
 
@@ -5567,8 +5568,10 @@ bool syntax_present(win_T *win)
 
 
 static enum {
-  EXP_SUBCMD,       /* expand ":syn" sub-commands */
-  EXP_CASE          /* expand ":syn case" arguments */
+  EXP_SUBCMD,       // expand ":syn" sub-commands
+  EXP_CASE,         // expand ":syn case" arguments
+  EXP_SPELL,        // expand ":syn spell" arguments
+  EXP_SYNC          // expand ":syn sync" arguments
 } expand_what;
 
 /*
@@ -5612,6 +5615,10 @@ void set_context_in_syntax_cmd(expand_T *xp, const char *arg)
         xp->xp_context = EXPAND_NOTHING;
       } else if (STRNICMP(arg, "case", p - arg) == 0) {
         expand_what = EXP_CASE;
+      } else if (STRNICMP(arg, "spell", p - arg) == 0) {
+        expand_what = EXP_SPELL;
+      } else if (STRNICMP(arg, "sync", p - arg) == 0) {
+        expand_what = EXP_SYNC;
       } else if (STRNICMP(arg, "keyword", p - arg) == 0
                  || STRNICMP(arg, "region", p - arg) == 0
                  || STRNICMP(arg, "match", p - arg) == 0
@@ -5624,17 +5631,33 @@ void set_context_in_syntax_cmd(expand_T *xp, const char *arg)
   }
 }
 
-static char *(case_args[]) = {"match", "ignore", NULL};
-
 /*
  * Function given to ExpandGeneric() to obtain the list syntax names for
  * expansion.
  */
 char_u *get_syntax_name(expand_T *xp, int idx)
 {
-  if (expand_what == EXP_SUBCMD)
-    return (char_u *)subcommands[idx].name;
-  return (char_u *)case_args[idx];
+  switch (expand_what) {
+    case EXP_SUBCMD:
+        return (char_u *)subcommands[idx].name;
+    case EXP_CASE: {
+        static char *case_args[] = { "match", "ignore", NULL };
+        return (char_u *)case_args[idx];
+    }
+    case EXP_SPELL: {
+        static char *spell_args[] =
+        { "toplevel", "notoplevel", "default", NULL };
+        return (char_u *)spell_args[idx];
+    }
+    case EXP_SYNC: {
+        static char *sync_args[] =
+        { "ccomment", "clear", "fromstart",
+         "linebreaks=", "linecont", "lines=", "match",
+         "maxlines=", "minlines=", "region", NULL };
+        return (char_u *)sync_args[idx];
+    }
+  }
+  return NULL;
 }
 
 
@@ -6622,7 +6645,6 @@ do_highlight(char_u *line, int forceit, int init) {
     syn_unadd_group();
   } else {
     if (is_normal_group) {
-      HL_TABLE()[idx].sg_attr = 0;
       // Need to update all groups, because they might be using "bg" and/or
       // "fg", which have been changed now.
       highlight_attr_set_all();
@@ -6825,8 +6847,6 @@ int hl_combine_attr(int char_attr, int prim_attr)
   if (char_aep != NULL) {
     // Copy all attributes from char_aep to the new entry
     new_en = *char_aep;
-  } else {
-    memset(&new_en, 0, sizeof(new_en));
   }
 
   spell_aep = syn_cterm_attr2entry(prim_attr);
@@ -6859,6 +6879,7 @@ int hl_combine_attr(int char_attr, int prim_attr)
 
 /// \note this function does not apply exclusively to cterm attr contrary
 /// to what its name implies
+/// \warn don't call it with attr 0 (i.e., the null attribute)
 attrentry_T *syn_cterm_attr2entry(int attr)
 {
   attr -= ATTR_OFF;
@@ -7103,22 +7124,14 @@ syn_list_header(int did_header, int outlen, int id)
   return newline;
 }
 
-/*
- * Set the attribute numbers for a highlight group.
- * Called after one of the attributes has changed.
- */
-static void 
-set_hl_attr (
-    int idx                    /* index in array */
-)
+/// Set the attribute numbers for a highlight group.
+/// Called after one of the attributes has changed.
+/// @param idx corrected highlight index
+static void set_hl_attr(int idx)
 {
   attrentry_T at_en = ATTRENTRY_INIT;
   struct hl_group     *sgp = HL_TABLE() + idx;
 
-  // The "Normal" group doesn't need an attribute number
-  if (sgp->sg_name_u != NULL && STRCMP(sgp->sg_name_u, "NORMAL") == 0) {
-    return;
-  }
 
   at_en.cterm_ae_attr = sgp->sg_cterm;
   at_en.cterm_fg_color = sgp->sg_cterm_fg;
@@ -8227,6 +8240,30 @@ RgbValue name_to_color(const uint8_t *name)
   return -1;
 }
 
+/// Gets highlight description for id `attr_id` as a map.
+Dictionary hl_get_attr_by_id(Integer attr_id, Boolean rgb, Error *err)
+{
+  HlAttrs attrs = HLATTRS_INIT;
+  Dictionary dic = ARRAY_DICT_INIT;
+
+  if (attr_id == 0) {
+    goto end;
+  }
+
+  attrentry_T *aep = syn_cterm_attr2entry((int)attr_id);
+  if (!aep) {
+    api_set_error(err, kErrorTypeException,
+                  "Invalid attribute id: %d", attr_id);
+    return dic;
+  }
+
+  attrs = attrentry2hlattrs(aep, rgb);
+
+end:
+  return hlattrs2dict(attrs);
+}
+
+
 /**************************************
 *  End of Highlighting stuff	      *
 **************************************/
diff --git a/src/nvim/testdir/Makefile b/src/nvim/testdir/Makefile
index 9133bfc0a2..38caa8815d 100644
--- a/src/nvim/testdir/Makefile
+++ b/src/nvim/testdir/Makefile
@@ -59,6 +59,7 @@ NEW_TESTS ?= \
 	    test_matchadd_conceal.res \
 	    test_matchadd_conceal_utf8.res \
 	    test_mksession.res \
+	    test_mksession_utf8.res \
 	    test_nested_function.res \
 	    test_normal.res \
 	    test_quickfix.res \
diff --git a/src/nvim/testdir/test_syntax.vim b/src/nvim/testdir/test_syntax.vim
index af2cbbfe8e..05e930d984 100644
--- a/src/nvim/testdir/test_syntax.vim
+++ b/src/nvim/testdir/test_syntax.vim
@@ -76,3 +76,11 @@ func Test_syntax_after_reload()
   call assert_true(exists('g:gotit'))
   call delete('Xsomefile')
 endfunc
+
+func Test_syntax_completion()
+  call feedkeys(":syn spell \<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"syn spell default notoplevel toplevel', @:)
+
+  call feedkeys(":syn sync \<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"syn sync ccomment clear fromstart linebreaks= linecont lines= match maxlines= minlines= region', @:)
+endfunc
diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index 256772489d..8e0e905bcd 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -288,7 +288,7 @@ static void terminfo_stop(UI *ui)
 static void tui_terminal_start(UI *ui)
 {
   TUIData *data = ui->data;
-  data->print_attrs = EMPTY_ATTRS;
+  data->print_attrs = HLATTRS_INIT;
   ugrid_init(&data->grid);
   terminfo_start(ui);
   update_size(ui);
@@ -628,7 +628,7 @@ static void clear_region(UI *ui, int top, int bot, int left, int right)
   if (grid->bg == -1 && right == ui->width -1) {
     // Background is set to the default color and the right edge matches the
     // screen end, try to use terminal codes for clearing the requested area.
-    HlAttrs clear_attrs = EMPTY_ATTRS;
+    HlAttrs clear_attrs = HLATTRS_INIT;
     clear_attrs.foreground = grid->fg;
     clear_attrs.background = grid->bg;
     update_attrs(ui, clear_attrs);
@@ -926,7 +926,7 @@ static void tui_scroll(UI *ui, Integer count)
     cursor_goto(ui, grid->top, grid->left);
     // also set default color attributes or some terminals can become funny
     if (scroll_clears_to_current_colour) {
-      HlAttrs clear_attrs = EMPTY_ATTRS;
+      HlAttrs clear_attrs = HLATTRS_INIT;
       clear_attrs.foreground = grid->fg;
       clear_attrs.background = grid->bg;
       update_attrs(ui, clear_attrs);
diff --git a/src/nvim/ugrid.c b/src/nvim/ugrid.c
index 7a0a16687e..2b5e96ee60 100644
--- a/src/nvim/ugrid.c
+++ b/src/nvim/ugrid.c
@@ -16,7 +16,7 @@
 
 void ugrid_init(UGrid *grid)
 {
-  grid->attrs = EMPTY_ATTRS;
+  grid->attrs = HLATTRS_INIT;
   grid->fg = grid->bg = -1;
   grid->cells = NULL;
 }
@@ -118,7 +118,7 @@ UCell *ugrid_put(UGrid *grid, uint8_t *text, size_t size)
 
 static void clear_region(UGrid *grid, int top, int bot, int left, int right)
 {
-  HlAttrs clear_attrs = EMPTY_ATTRS;
+  HlAttrs clear_attrs = HLATTRS_INIT;
   clear_attrs.foreground = grid->fg;
   clear_attrs.background = grid->bg;
   UGRID_FOREACH_CELL(grid, top, bot, left, right, {
diff --git a/src/nvim/ugrid.h b/src/nvim/ugrid.h
index 268362bf1b..1cf047502d 100644
--- a/src/nvim/ugrid.h
+++ b/src/nvim/ugrid.h
@@ -21,8 +21,6 @@ struct ugrid {
   UCell **cells;
 };
 
-#define EMPTY_ATTRS ((HlAttrs){ false, false, false, false, false, -1, -1, -1 })
-
 #define UGRID_FOREACH_CELL(grid, top, bot, left, right, code) \
   do { \
     for (int row = top; row <= bot; row++) { \
diff --git a/src/nvim/ui.c b/src/nvim/ui.c
index 01d3604159..afe7a51d43 100644
--- a/src/nvim/ui.c
+++ b/src/nvim/ui.c
@@ -166,6 +166,90 @@ void ui_event(char *name, Array args)
   }
 }
 
+
+/// Converts an attrentry_T into an HlAttrs
+///
+/// @param[in] aep data to convert
+/// @param use_rgb use 'gui*' settings if true, else resorts to 'cterm*'
+HlAttrs attrentry2hlattrs(const attrentry_T *aep, bool use_rgb)
+{
+  assert(aep);
+
+  HlAttrs attrs = HLATTRS_INIT;
+  int mask = 0;
+
+  mask = use_rgb ? aep->rgb_ae_attr : aep->cterm_ae_attr;
+
+  attrs.bold = mask & HL_BOLD;
+  attrs.underline = mask & HL_UNDERLINE;
+  attrs.undercurl = mask & HL_UNDERCURL;
+  attrs.italic = mask & HL_ITALIC;
+  attrs.reverse = mask & (HL_INVERSE | HL_STANDOUT);
+
+  if (use_rgb) {
+    if (aep->rgb_fg_color != -1) {
+      attrs.foreground = aep->rgb_fg_color;
+    }
+
+    if (aep->rgb_bg_color != -1) {
+      attrs.background = aep->rgb_bg_color;
+    }
+
+    if (aep->rgb_sp_color != -1) {
+      attrs.special = aep->rgb_sp_color;
+    }
+  } else {
+    if (cterm_normal_fg_color != aep->cterm_fg_color) {
+      attrs.foreground = aep->cterm_fg_color - 1;
+    }
+
+    if (cterm_normal_bg_color != aep->cterm_bg_color) {
+        attrs.background = aep->cterm_bg_color - 1;
+    }
+  }
+
+  return attrs;
+}
+
+Dictionary hlattrs2dict(HlAttrs attrs)
+{
+  Dictionary hl = ARRAY_DICT_INIT;
+
+  if (attrs.bold) {
+    PUT(hl, "bold", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.underline) {
+    PUT(hl, "underline", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.undercurl) {
+    PUT(hl, "undercurl", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.italic) {
+    PUT(hl, "italic", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.reverse) {
+    PUT(hl, "reverse", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.foreground != -1) {
+    PUT(hl, "foreground", INTEGER_OBJ(attrs.foreground));
+  }
+
+  if (attrs.background != -1) {
+    PUT(hl, "background", INTEGER_OBJ(attrs.background));
+  }
+
+  if (attrs.special != -1) {
+    PUT(hl, "special", INTEGER_OBJ(attrs.special));
+  }
+
+  return hl;
+}
+
 void ui_refresh(void)
 {
   if (!ui_active()) {
@@ -405,54 +489,20 @@ void ui_flush(void)
 
 static void set_highlight_args(int attr_code)
 {
-  HlAttrs rgb_attrs = { false, false, false, false, false, -1, -1, -1 };
+  HlAttrs rgb_attrs = HLATTRS_INIT;
   HlAttrs cterm_attrs = rgb_attrs;
 
   if (attr_code == HL_NORMAL) {
     goto end;
   }
-
-  int rgb_mask = 0;
-  int cterm_mask = 0;
   attrentry_T *aep = syn_cterm_attr2entry(attr_code);
 
   if (!aep) {
     goto end;
   }
 
-  rgb_mask = aep->rgb_ae_attr;
-  cterm_mask = aep->cterm_ae_attr;
-
-  rgb_attrs.bold = rgb_mask & HL_BOLD;
-  rgb_attrs.underline = rgb_mask & HL_UNDERLINE;
-  rgb_attrs.undercurl = rgb_mask & HL_UNDERCURL;
-  rgb_attrs.italic = rgb_mask & HL_ITALIC;
-  rgb_attrs.reverse = rgb_mask & (HL_INVERSE | HL_STANDOUT);
-  cterm_attrs.bold = cterm_mask & HL_BOLD;
-  cterm_attrs.underline = cterm_mask & HL_UNDERLINE;
-  cterm_attrs.undercurl = cterm_mask & HL_UNDERCURL;
-  cterm_attrs.italic = cterm_mask & HL_ITALIC;
-  cterm_attrs.reverse = cterm_mask & (HL_INVERSE | HL_STANDOUT);
-
-  if (aep->rgb_fg_color != normal_fg) {
-    rgb_attrs.foreground = aep->rgb_fg_color;
-  }
-
-  if (aep->rgb_bg_color != normal_bg) {
-    rgb_attrs.background = aep->rgb_bg_color;
-  }
-
-  if (aep->rgb_sp_color != normal_sp) {
-    rgb_attrs.special = aep->rgb_sp_color;
-  }
-
-  if (cterm_normal_fg_color != aep->cterm_fg_color) {
-    cterm_attrs.foreground = aep->cterm_fg_color - 1;
-  }
-
-  if (cterm_normal_bg_color != aep->cterm_bg_color) {
-    cterm_attrs.background = aep->cterm_bg_color - 1;
-  }
+  rgb_attrs = attrentry2hlattrs(aep, true);
+  cterm_attrs = attrentry2hlattrs(aep, false);
 
 end:
   UI_CALL(highlight_set, (ui->rgb ? rgb_attrs : cterm_attrs));
diff --git a/src/nvim/ui.h b/src/nvim/ui.h
index 064f77fee1..f1ea0716e6 100644
--- a/src/nvim/ui.h
+++ b/src/nvim/ui.h
@@ -21,6 +21,9 @@ typedef struct {
   int foreground, background, special;
 } HlAttrs;
 
+#define HLATTRS_INIT \
+  ((HlAttrs){ false, false, false, false, false, -1, -1, -1 })
+
 typedef struct ui_t UI;
 
 struct ui_t {
diff --git a/src/nvim/version.c b/src/nvim/version.c
index 54e4cc9bba..6729adaff3 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -939,14 +939,14 @@ static const int included_patches[] = {
   167,
   // 166,
   165,
-  // 164,
+  164,
   // 163 NA
   // 162 NA
   // 161 NA
   // 160,
   159,
   158,
-  // 157,
+  157,
   156,
   // 155,
   // 154,
@@ -955,13 +955,13 @@ static const int included_patches[] = {
   // 151,
   150,
   149,
-  // 148,
+  148,
   147,
   146,
   // 145 NA
   // 144 NA
   143,
-  // 142,
+  142,
   // 141,
   // 140,
   // 139 NA