1 files changed, 51 insertions, 36 deletions

diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 478fa973a1..b04180ad1c 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -2615,33 +2615,37 @@ find_endpos (
                           IF_SYN_TIME(&spp_skip->sp_time));
       spp_skip->sp_prog = regmatch.regprog;
       if (r && regmatch.startpos[0].col <= best_regmatch.startpos[0].col) {
-        /* Add offset to skip pattern match */
+        // Add offset to skip pattern match
         syn_add_end_off(&pos, &regmatch, spp_skip, SPO_ME_OFF, 1);
 
-        /* If the skip pattern goes on to the next line, there is no
-         * match with an end pattern in this line. */
-        if (pos.lnum > startpos->lnum)
+        // If the skip pattern goes on to the next line, there is no
+        // match with an end pattern in this line.
+        if (pos.lnum > startpos->lnum) {
           break;
+        }
 
-        line = ml_get_buf(syn_buf, startpos->lnum, FALSE);
+        line = ml_get_buf(syn_buf, startpos->lnum, false);
+        int line_len = (int)STRLEN(line);
 
-        /* take care of an empty match or negative offset */
-        if (pos.col <= matchcol)
-          ++matchcol;
-        else if (pos.col <= regmatch.endpos[0].col)
+        // take care of an empty match or negative offset
+        if (pos.col <= matchcol) {
+          matchcol++;
+        } else if (pos.col <= regmatch.endpos[0].col) {
           matchcol = pos.col;
-        else
-          /* Be careful not to jump over the NUL at the end-of-line */
+        } else {
+          // Be careful not to jump over the NUL at the end-of-line
           for (matchcol = regmatch.endpos[0].col;
-               line[matchcol] != NUL && matchcol < pos.col;
-               ++matchcol)
-            ;
+               matchcol < line_len && matchcol < pos.col;
+               matchcol++) {
+          }
+        }
 
-        /* if the skip pattern includes end-of-line, break here */
-        if (line[matchcol] == NUL)
+        // if the skip pattern includes end-of-line, break here
+        if (matchcol >= line_len) {
           break;
+        }
 
-        continue;                   /* start with first end pattern again */
+        continue;  // start with first end pattern again
       }
     }
 
@@ -4478,12 +4482,10 @@ syn_cmd_region (
   if (illegal || not_enough)
     rest = NULL;
 
-  /*
-   * Must have a "start" and "end" pattern.
-   */
-  if (rest != NULL && (pat_ptrs[ITEM_START] == NULL ||
-                       pat_ptrs[ITEM_END] == NULL)) {
-    not_enough = TRUE;
+  // Must have a "start" and "end" pattern.
+  if (rest != NULL && (pat_ptrs[ITEM_START] == NULL
+                       || pat_ptrs[ITEM_END] == NULL)) {
+    not_enough = true;
     rest = NULL;
   }
 
@@ -5006,6 +5008,10 @@ static void syn_cmd_sync(exarg_T *eap, int syncing)
         curwin->w_s->b_syn_sync_maxlines = 0;
       }
     } else if (STRCMP(key, "LINECONT") == 0)   {
+      if (*next_arg == NUL) {  // missing pattern
+        illegal = true;
+        break;
+      }
       if (curwin->w_s->b_syn_linecont_pat != NULL) {
         EMSG(_("E403: syntax sync: line continuations pattern specified twice"));
         finished = TRUE;
@@ -5533,25 +5539,29 @@ char_u *get_syntax_name(expand_T *xp, int idx)
 }
 
 
-/*
- * Function called for expression evaluation: get syntax ID at file position.
- */
-int 
-syn_get_id (
+// Function called for expression evaluation: get syntax ID at file position.
+int syn_get_id(
     win_T *wp,
     long lnum,
     colnr_T col,
-    int trans,                  /* remove transparency */
-    bool *spellp,               /* return: can do spell checking */
-    int keep_state              /* keep state of char at "col" */
+    int trans,      // remove transparency
+    bool *spellp,   // return: can do spell checking
+    int keep_state  // keep state of char at "col"
 )
 {
-  /* When the position is not after the current position and in the same
-   * line of the same buffer, need to restart parsing. */
+  // When the position is not after the current position and in the same
+  // line of the same buffer, need to restart parsing.
   if (wp->w_buffer != syn_buf
       || lnum != current_lnum
-      || col < current_col)
+      || col < current_col) {
     syntax_start(wp, lnum);
+  } else if (wp->w_buffer == syn_buf
+             && lnum == current_lnum
+             && col > current_col) {
+      // next_match may not be correct when moving around, e.g. with the
+      // "skip" expression in searchpair()
+      next_match_idx = -1;
+  }
 
   (void)get_syntax_attr(col, spellp, keep_state);
 
@@ -6391,7 +6401,7 @@ do_highlight (
             HL_TABLE()[idx].sg_cterm_bg = color + 1;
             if (is_normal_group) {
               cterm_normal_bg_color = color + 1;
-              {
+              if (!ui_rgb_attached()) {
                 must_redraw = CLEAR;
                 if (color >= 0) {
                   if (t_colors < 16)
@@ -6929,7 +6939,12 @@ set_hl_attr (
   // before setting attr_entry->{f,g}g_color to a other than -1
   at_en.rgb_fg_color = sgp->sg_rgb_fg_name ? sgp->sg_rgb_fg : -1;
   at_en.rgb_bg_color = sgp->sg_rgb_bg_name ? sgp->sg_rgb_bg : -1;
-  sgp->sg_attr = get_attr_entry(&at_en);
+
+  if (at_en.cterm_fg_color != 0 || at_en.cterm_bg_color != 0
+      || at_en.rgb_fg_color != -1 || at_en.rgb_bg_color != -1
+      || at_en.cterm_ae_attr != 0 || at_en.rgb_ae_attr != 0) {
+    sgp->sg_attr = get_attr_entry(&at_en);
+  }
 }
 
 /*