fix(decor): don't use separate DecorSignHighlight for url (#30096)

(cherry picked from commit a8fbe1d409)

src/nvim/api/extmark.c

@@ -691,6 +691,7 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
 
   if (HAS_KEY(opts, set_extmark, url)) {
     url = string_to_cstr(opts->url);
+    has_hl = true;
   }
 
   if (opts->ui_watched) {
@@ -767,13 +768,9 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     if (kv_size(virt_lines.data.virt_lines)) {
       decor_range_add_virt(&decor_state, r, c, line2, col2, decor_put_vt(virt_lines, NULL), true);
     }
-    if (url != NULL) {
-      DecorSignHighlight sh = DECOR_SIGN_HIGHLIGHT_INIT;
-      sh.url = url;
-      decor_range_add_sh(&decor_state, r, c, line2, col2, &sh, true, 0, 0);
-    }
     if (has_hl) {
       DecorSignHighlight sh = decor_sh_from_inline(hl);
+      sh.url = url;
       decor_range_add_sh(&decor_state, r, c, line2, col2, &sh, true, (uint32_t)ns_id, id);
     }
   } else {
@@ -797,12 +794,7 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     }
 
     uint32_t decor_indexed = DECOR_ID_INVALID;
-    if (url != NULL) {
+
-      DecorSignHighlight sh = DECOR_SIGN_HIGHLIGHT_INIT;
-      sh.url = url;
-      sh.next = decor_indexed;
-      decor_indexed = decor_put_sh(sh);
-    }
     if (sign.flags & kSHIsSign) {
       sign.next = decor_indexed;
       decor_indexed = decor_put_sh(sign);
@@ -815,9 +807,11 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     }
 
     DecorInline decor = DECOR_INLINE_INIT;
-    if (decor_alloc || decor_indexed != DECOR_ID_INVALID || schar_high(hl.conceal_char)) {
+    if (decor_alloc || decor_indexed != DECOR_ID_INVALID || url != NULL
+        || schar_high(hl.conceal_char)) {
       if (has_hl) {
         DecorSignHighlight sh = decor_sh_from_inline(hl);
+        sh.url = url;
         sh.next = decor_indexed;
         decor_indexed = decor_put_sh(sh);
       }

test/functional/api/extmark_spec.lua

@@ -1798,10 +1798,15 @@ describe('API/extmarks', function()
   end)
 
   it('can set a URL', function()
-    set_extmark(ns, 1, 0, 0, { url = 'https://example.com', end_col = 3 })
+    local url1 = 'https://example.com'
+    local url2 = 'http://127.0.0.1'
+    set_extmark(ns, 1, 0, 0, { url = url1, end_col = 3 })
+    set_extmark(ns, 2, 0, 3, { url = url2, hl_group = 'Search', end_col = 5 })
     local extmarks = get_extmarks(ns, 0, -1, { details = true })
-    eq(1, #extmarks)
+    eq(2, #extmarks)
-    eq('https://example.com', extmarks[1][4].url)
+    eq(url1, extmarks[1][4].url)
+    eq(url2, extmarks[2][4].url)
+    eq('Search', extmarks[2][4].hl_group)
   end)
 
   it('respects priority', function()

test/functional/ui/decorations_spec.lua

@@ -2341,21 +2341,28 @@ describe('extmark decorations', function()
   it('supports URLs', function()
     insert(example_text)
 
-    local url = 'https://example.com'
+    local url1 = 'https://example.com'
+    local url2 = 'http://127.0.0.1'
 
     screen:add_extra_attr_ids {
-        u = { url = "https://example.com" },
+      u = { url = url1 },
+      uh = { url = url2, background = Screen.colors.Yellow },
     }
 
     api.nvim_buf_set_extmark(0, ns, 1, 4, {
       end_col = 14,
-      url = url,
+      url = url1,
+    })
+    api.nvim_buf_set_extmark(0, ns, 2, 4, {
+      end_col = 17,
+      hl_group = 'Search',
+      url = url2,
     })
 
-    screen:expect{grid=[[
+    screen:expect([[
       for _,item in ipairs(items) do                    |
           {u:local text}, hl_id_cell, count = unpack(item)  |
-          if hl_id_cell ~= nil then                     |
+          {uh:if hl_id_cell} ~= nil then                     |
               hl_id = hl_id_cell                        |
           end                                           |
           for _ = 1, (count or 1) do                    |
@@ -2368,7 +2375,7 @@ describe('extmark decorations', function()
       {1:~                                                 }|
       {1:~                                                 }|
                                                         |
-    ]]}
+    ]])
   end)
 
   it('can replace marks in place with different decorations #27211', function()