Merge #4851

3 files changed, 48 insertions, 9 deletions

diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 9e4dc0204f..05141eaf1e 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -6952,8 +6952,23 @@ highlight_color (
   else if (!(TOLOWER_ASC(what[0]) == 'b' && TOLOWER_ASC(what[1]) == 'g'))
     return NULL;
   if (modec == 'g') {
-    if (fg)
+    if (what[2] == '#' && ui_rgb_attached()) {
+      if (fg) {
+          n = HL_TABLE()[id - 1].sg_rgb_fg;
+      } else if (sp) {
+          n = HL_TABLE()[id - 1].sg_rgb_sp;
+      } else {
+          n = HL_TABLE()[id - 1].sg_rgb_bg;
+      }
+      if (n < 0 || n > 0xffffff) {
+        return NULL;
+      }
+      snprintf((char *)name, sizeof(name), "#%06x", n);
+      return name;
+    }
+    if (fg) {
       return HL_TABLE()[id - 1].sg_rgb_fg_name;
+    }
     if (sp) {
       return HL_TABLE()[id - 1].sg_rgb_sp_name;
     }
diff --git a/test/functional/terminal/highlight_spec.lua b/test/functional/terminal/highlight_spec.lua
index 8876c68673..8d7c7451d3 100644
--- a/test/functional/terminal/highlight_spec.lua
+++ b/test/functional/terminal/highlight_spec.lua
@@ -165,24 +165,49 @@ end)
 
 describe('synIDattr()', function()
   local screen
-
   before_each(function()
     clear()
     screen = Screen.new(50, 7)
-    execute('highlight Normal ctermfg=1 guifg=#ff0000')
+    execute('highlight Normal ctermfg=252 guifg=#ff0000 guibg=Black')
+    -- Salmon #fa8072 Maroon #800000
+    execute('highlight Keyword ctermfg=79 guifg=Salmon guisp=Maroon')
+  end)
+
+  it('returns cterm-color if RGB-capable UI is _not_ attached', function()
+    eq('252', eval('synIDattr(hlID("Normal"),  "fg")'))
+    eq('252', eval('synIDattr(hlID("Normal"),  "fg#")'))
+    eq('-1',  eval('synIDattr(hlID("Normal"),  "bg")'))
+    eq('-1',  eval('synIDattr(hlID("Normal"),  "bg#")'))
+    eq('79',  eval('synIDattr(hlID("Keyword"), "fg")'))
+    eq('79',  eval('synIDattr(hlID("Keyword"), "fg#")'))
+    eq('',    eval('synIDattr(hlID("Keyword"), "sp")'))
+    eq('',    eval('synIDattr(hlID("Keyword"), "sp#")'))
   end)
 
-  after_each(function()
-    screen:detach()
+  it('returns gui-color if "gui" arg is passed', function()
+    eq('Black',  eval('synIDattr(hlID("Normal"),  "bg", "gui")'))
+    eq('Maroon', eval('synIDattr(hlID("Keyword"), "sp", "gui")'))
+  end)
+
+  it('returns gui-color if RGB-capable UI is attached', function()
+    screen:attach(true)
+    eq('#ff0000', eval('synIDattr(hlID("Normal"),  "fg")'))
+    eq('Black',   eval('synIDattr(hlID("Normal"),  "bg")'))
+    eq('Salmon',  eval('synIDattr(hlID("Keyword"), "fg")'))
+    eq('Maroon',  eval('synIDattr(hlID("Keyword"), "sp")'))
   end)
 
-  it('returns RGB number if GUI', function()
+  it('returns #RRGGBB value for fg#/bg#/sp#', function()
     screen:attach(true)
-    eq('#ff0000', eval('synIDattr(hlID("Normal"), "fg")'))
+    eq('#ff0000', eval('synIDattr(hlID("Normal"), "fg#")'))
+    eq('#000000', eval('synIDattr(hlID("Normal"), "bg#")'))
+    eq('#fa8072', eval('synIDattr(hlID("Keyword"), "fg#")'))
+    eq('#800000', eval('synIDattr(hlID("Keyword"), "sp#")'))
   end)
 
   it('returns color number if non-GUI', function()
     screen:attach(false)
-    eq('1', eval('synIDattr(hlID("Normal"), "fg")'))
+    eq('252', eval('synIDattr(hlID("Normal"), "fg")'))
+    eq('79', eval('synIDattr(hlID("Keyword"), "fg")'))
   end)
 end)
diff --git a/test/functional/ui/highlight_spec.lua b/test/functional/ui/highlight_spec.lua
index b156f13885..6ef40fff62 100644
--- a/test/functional/ui/highlight_spec.lua
+++ b/test/functional/ui/highlight_spec.lua
@@ -38,7 +38,6 @@ describe('manual syntax highlight', function()
     os.remove('Xtest-functional-ui-highlight.tmp.vim')
   end)
 
-  -- test with "set hidden" even if the bug did not occur this way
   it("works with buffer switch and 'hidden'", function()
     execute('e tmp1.vim')
     execute('e Xtest-functional-ui-highlight.tmp.vim')