patch 8.2.0804: libvterm code lags behind the upstream version

Problem:    Libvterm code lags behind the upstream version.
Solution:   Include revision 727, but add the index instead of switching
            between RGB and indexed.
diff --git a/src/libvterm/t/26state_query.test b/src/libvterm/t/26state_query.test
index c6be90b..c543b92 100644
--- a/src/libvterm/t/26state_query.test
+++ b/src/libvterm/t/26state_query.test
@@ -41,10 +41,10 @@
 PUSH "\eP\$qm\e\\"
   output "\eP1\$r93;104m\e\\"
 
-!DECRQSS on SGR 256-palette colours
-PUSH "\e[0;38:5:56;48:5:78m"
-PUSH "\eP\$qm\e\\"
-  output "\eP1\$r38:5:56;48:5:78m\e\\"
+##!DECRQSS on SGR 256-palette colours
+#PUSH "\e[0;38:5:56;48:5:78m"
+#PUSH "\eP\$qm\e\\"
+#  output "\eP1\$r38:5:56;48:5:78m\e\\"
 
 !DECRQSS on SGR RGB8 colours
 PUSH "\e[0;38:2:24:68:112;48:2:13:57:101m"
diff --git a/src/libvterm/t/30state_pen.test b/src/libvterm/t/30state_pen.test
index d1e0d14..915baec 100644
--- a/src/libvterm/t/30state_pen.test
+++ b/src/libvterm/t/30state_pen.test
@@ -10,8 +10,8 @@
   ?pen blink = off
   ?pen reverse = off
   ?pen font = 0
-  ?pen foreground = rgb(240,240,240)
-  ?pen background = rgb(0,0,0)
+  ?pen foreground = rgb(240,240,240,is_default_fg)
+  ?pen background = rgb(0,0,0,is_default_bg)
 
 !Bold
 PUSH "\e[1m"
@@ -75,40 +75,40 @@
 
 !Foreground
 PUSH "\e[31m"
-  ?pen foreground = rgb(224,0,0)
+  ?pen foreground = idx(1)
 PUSH "\e[32m"
-  ?pen foreground = rgb(0,224,0)
+  ?pen foreground = idx(2)
 PUSH "\e[34m"
-  ?pen foreground = rgb(0,0,224)
+  ?pen foreground = idx(4)
 PUSH "\e[91m"
-  ?pen foreground = rgb(255,64,64)
+  ?pen foreground = idx(9)
 PUSH "\e[38:2:10:20:30m"
   ?pen foreground = rgb(10,20,30)
 PUSH "\e[38:5:1m"
-  ?pen foreground = rgb(224,0,0)
+  ?pen foreground = idx(1)
 PUSH "\e[39m"
-  ?pen foreground = rgb(240,240,240)
+  ?pen foreground = rgb(240,240,240,is_default_fg)
 
 !Background
 PUSH "\e[41m"
-  ?pen background = rgb(224,0,0)
+  ?pen background = idx(1)
 PUSH "\e[42m"
-  ?pen background = rgb(0,224,0)
+  ?pen background = idx(2)
 PUSH "\e[44m"
-  ?pen background = rgb(0,0,224)
+  ?pen background = idx(4)
 PUSH "\e[101m"
-  ?pen background = rgb(255,64,64)
+  ?pen background = idx(9)
 PUSH "\e[48:2:10:20:30m"
   ?pen background = rgb(10,20,30)
 PUSH "\e[48:5:1m"
-  ?pen background = rgb(224,0,0)
+  ?pen background = idx(1)
 PUSH "\e[49m"
-  ?pen background = rgb(0,0,0)
+  ?pen background = rgb(0,0,0,is_default_bg)
 
 !Bold+ANSI colour == highbright
 PUSH "\e[m\e[1;37m"
   ?pen bold = on
-  ?pen foreground = rgb(255,255,255)
+  ?pen foreground = idx(15)
 PUSH "\e[m\e[37;1m"
   ?pen bold = on
-  ?pen foreground = rgb(255,255,255)
+  ?pen foreground = idx(15)
diff --git a/src/libvterm/t/64screen_pen.test b/src/libvterm/t/64screen_pen.test
index f1ee639..3a78140 100644
--- a/src/libvterm/t/64screen_pen.test
+++ b/src/libvterm/t/64screen_pen.test
@@ -29,27 +29,27 @@
 
 !Foreground
 PUSH "\e[31mG\e[m"
-  ?screen_cell 0,6 = {0x47} width=1 attrs={} fg=rgb(224,0,0) bg=rgb(0,0,0)
+  ?screen_cell 0,6 = {0x47} width=1 attrs={} fg=idx(1) bg=rgb(0,0,0)
 
 !Background
 PUSH "\e[42mH\e[m"
-  ?screen_cell 0,7 = {0x48} width=1 attrs={} fg=rgb(240,240,240) bg=rgb(0,224,0)
+  ?screen_cell 0,7 = {0x48} width=1 attrs={} fg=rgb(240,240,240) bg=idx(2)
 
 !EL sets reverse and colours to end of line
 PUSH "\e[H\e[7;33;44m\e[K"
-  ?screen_cell 0,0  = {} width=1 attrs={R} fg=rgb(224,224,0) bg=rgb(0,0,224)
-  ?screen_cell 0,79 = {} width=1 attrs={R} fg=rgb(224,224,0) bg=rgb(0,0,224)
+  ?screen_cell 0,0  = {} width=1 attrs={R} fg=idx(3) bg=idx(4)
+  ?screen_cell 0,79 = {} width=1 attrs={R} fg=idx(3) bg=idx(4)
 
 !DECSCNM xors reverse for entire screen
 PUSH "\e[?5h"
-  ?screen_cell 0,0  = {} width=1 attrs={} fg=rgb(224,224,0) bg=rgb(0,0,224)
-  ?screen_cell 0,79 = {} width=1 attrs={} fg=rgb(224,224,0) bg=rgb(0,0,224)
+  ?screen_cell 0,0  = {} width=1 attrs={} fg=idx(3) bg=idx(4)
+  ?screen_cell 0,79 = {} width=1 attrs={} fg=idx(3) bg=idx(4)
   ?screen_cell 1,0  = {} width=1 attrs={R} fg=rgb(240,240,240) bg=rgb(0,0,0)
 PUSH "\e[?5\$p"
   output "\e[?5;1\$y"
 PUSH "\e[?5l"
-  ?screen_cell 0,0  = {} width=1 attrs={R} fg=rgb(224,224,0) bg=rgb(0,0,224)
-  ?screen_cell 0,79 = {} width=1 attrs={R} fg=rgb(224,224,0) bg=rgb(0,0,224)
+  ?screen_cell 0,0  = {} width=1 attrs={R} fg=idx(3) bg=idx(4)
+  ?screen_cell 0,79 = {} width=1 attrs={R} fg=idx(3) bg=idx(4)
   ?screen_cell 1,0  = {} width=1 attrs={} fg=rgb(240,240,240) bg=rgb(0,0,0)
 PUSH "\e[?5\$p"
   output "\e[?5;2\$y"
diff --git a/src/libvterm/t/harness.c b/src/libvterm/t/harness.c
index fd129b7..10afbfd 100644
--- a/src/libvterm/t/harness.c
+++ b/src/libvterm/t/harness.c
@@ -60,6 +60,26 @@
   return VTERM_KEY_NONE;
 }
 
+static void print_color(const VTermColor *col)
+{
+  if (VTERM_COLOR_IS_RGB(col)) {
+    printf("rgb(%d,%d,%d", col->red, col->green, col->blue);
+  }
+  else if (VTERM_COLOR_IS_INDEXED(col)) {
+    printf("idx(%d", col->index);
+  }
+  else {
+    printf("invalid(%d", col->type);
+  }
+  if (VTERM_COLOR_IS_DEFAULT_FG(col)) {
+    printf(",is_default_fg");
+  }
+  if (VTERM_COLOR_IS_DEFAULT_BG(col)) {
+    printf(",is_default_bg");
+  }
+  printf(")");
+}
+
 static VTerm *vt;
 static VTermState *state;
 static VTermScreen *screen;
@@ -273,7 +293,9 @@
         val->string.initial ? "[" : "", val->string.len, val->string.str, val->string.final ? "]" : "");
     return 1;
   case VTERM_VALUETYPE_COLOR:
-    printf("settermprop %d rgb(%d,%d,%d)\n", prop, val->color.red, val->color.green, val->color.blue);
+    printf("settermprop %d ", prop);
+    print_color(&val->color);
+    printf("\n");
     return 1;
 
   case VTERM_N_VALUETYPES:
@@ -834,10 +856,12 @@
             printf("%d\n", state_pen.font);
         }
         else if(streq(linep, "foreground")) {
-          printf("rgb(%d,%d,%d)\n", state_pen.foreground.red, state_pen.foreground.green, state_pen.foreground.blue);
+          print_color(&state_pen.foreground);
+          printf("\n");
         }
         else if(streq(linep, "background")) {
-          printf("rgb(%d,%d,%d)\n", state_pen.background.red, state_pen.background.green, state_pen.background.blue);
+          print_color(&state_pen.background);
+          printf("\n");
         }
         else
           printf("?\n");
@@ -952,8 +976,13 @@
         printf("} ");
         if(cell.attrs.dwl)       printf("dwl ");
         if(cell.attrs.dhl)       printf("dhl-%s ", cell.attrs.dhl == 2 ? "bottom" : "top");
-        printf("fg=rgb(%d,%d,%d) ",  cell.fg.red, cell.fg.green, cell.fg.blue);
-        printf("bg=rgb(%d,%d,%d)\n", cell.bg.red, cell.bg.green, cell.bg.blue);
+        printf("fg=");
+        vterm_screen_convert_color_to_rgb(screen, &cell.fg);
+        print_color(&cell.fg);
+        printf(" bg=");
+        vterm_screen_convert_color_to_rgb(screen, &cell.bg);
+        print_color(&cell.bg);
+        printf("\n");
       }
       else if(strstartswith(line, "?screen_eol ")) {
         VTermPos pos;