feat(term): support OSC 8 hyperlinks in :terminal (#30050)

8 files changed, 173 insertions, 4 deletions

diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 68a05a99a4..7c842f42dd 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -166,6 +166,8 @@ TERMINAL
 • The terminal buffer now supports reflow (wrapped lines adapt when the buffer
   is resized horizontally). Note: Lines that are not visible and kept in
   'scrollback' are not reflown.
+• The |terminal| now supports OSC 8 escape sequences and will display
+  hyperlinks in supporting host terminals.
 
 TREESITTER
 
diff --git a/src/nvim/terminal.c b/src/nvim/terminal.c
index 54a0de9c22..2b44763ddd 100644
--- a/src/nvim/terminal.c
+++ b/src/nvim/terminal.c
@@ -227,11 +227,66 @@ static void schedule_termrequest(Terminal *term, char *payload, size_t payload_l
                  term->pending_send);
 }
 
+static int parse_osc8(VTermStringFragment frag, int *attr)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // Parse the URI from the OSC 8 sequence and add the URL to our URL set.
+  // Skip the ID, we don't use it (for now)
+  size_t i = 0;
+  for (; i < frag.len; i++) {
+    if (frag.str[i] == ';') {
+      break;
+    }
+  }
+
+  // Move past the semicolon
+  i++;
+
+  if (i >= frag.len) {
+    // Invalid OSC sequence
+    return 0;
+  }
+
+  // Find the terminator
+  const size_t start = i;
+  for (; i < frag.len; i++) {
+    if (frag.str[i] == '\a' || frag.str[i] == '\x1b') {
+      break;
+    }
+  }
+
+  const size_t len = i - start;
+  if (len == 0) {
+    // Empty OSC 8, no URL
+    *attr = 0;
+    return 1;
+  }
+
+  char *url = xmemdupz(&frag.str[start], len + 1);
+  url[len] = 0;
+  *attr = hl_add_url(0, url);
+  xfree(url);
+
+  return 1;
+}
+
 static int on_osc(int command, VTermStringFragment frag, void *user)
 {
+  Terminal *term = user;
+
   if (frag.str == NULL) {
     return 0;
   }
+
+  if (command == 8) {
+    int attr = 0;
+    if (parse_osc8(frag, &attr)) {
+      VTermState *state = vterm_obtain_state(term->vt);
+      VTermValue value = { .number = attr };
+      vterm_state_set_penattr(state, VTERM_ATTR_URI, VTERM_VALUETYPE_INT, &value);
+    }
+  }
+
   if (!has_event(EVENT_TERMREQUEST)) {
     return 1;
   }
@@ -239,7 +294,7 @@ static int on_osc(int command, VTermStringFragment frag, void *user)
   StringBuilder request = KV_INITIAL_VALUE;
   kv_printf(request, "\x1b]%d;", command);
   kv_concat_len(request, frag.str, frag.len);
-  schedule_termrequest(user, request.items, request.size);
+  schedule_termrequest(term, request.items, request.size);
   return 1;
 }
 
@@ -992,6 +1047,10 @@ void terminal_get_line_attributes(Terminal *term, win_T *wp, int linenr, int *te
       });
     }
 
+    if (cell.uri > 0) {
+      attr_id = hl_combine_attr(attr_id, cell.uri);
+    }
+
     if (term->cursor.visible && term->cursor.row == row
         && term->cursor.col == col) {
       attr_id = hl_combine_attr(attr_id,
diff --git a/src/vterm/pen.c b/src/vterm/pen.c
index 562005435e..1876eb9881 100644
--- a/src/vterm/pen.c
+++ b/src/vterm/pen.c
@@ -182,6 +182,8 @@ INTERNAL void vterm_state_resetpen(VTermState *state)
 
   state->pen.fg = state->default_fg;  setpenattr_col(state, VTERM_ATTR_FOREGROUND, state->default_fg);
   state->pen.bg = state->default_bg;  setpenattr_col(state, VTERM_ATTR_BACKGROUND, state->default_bg);
+
+  state->pen.uri = 0; setpenattr_int(state, VTERM_ATTR_URI, 0);
 }
 
 INTERNAL void vterm_state_savepen(VTermState *state, int save)
@@ -205,6 +207,8 @@ INTERNAL void vterm_state_savepen(VTermState *state, int save)
 
     setpenattr_col( state, VTERM_ATTR_FOREGROUND, state->pen.fg);
     setpenattr_col( state, VTERM_ATTR_BACKGROUND, state->pen.bg);
+
+    setpenattr_int( state, VTERM_ATTR_URI, state->pen.uri);
   }
 }
 
@@ -600,9 +604,75 @@ int vterm_state_get_penattr(const VTermState *state, VTermAttr attr, VTermValue
     val->number = state->pen.baseline;
     return 1;
 
+  case VTERM_ATTR_URI:
+    val->number = state->pen.uri;
+    return 1;
+
   case VTERM_N_ATTRS:
     return 0;
   }
 
   return 0;
 }
+
+int vterm_state_set_penattr(VTermState *state, VTermAttr attr, VTermValueType type, VTermValue *val)
+{
+  if (!val) {
+    return 0;
+  }
+
+  if(type != vterm_get_attr_type(attr)) {
+    DEBUG_LOG("Cannot set attr %d as it has type %d, not type %d\n",
+        attr, vterm_get_attr_type(attr), type);
+    return 0;
+  }
+
+  switch (attr) {
+  case VTERM_ATTR_BOLD:
+    state->pen.bold = val->boolean;
+    break;
+  case VTERM_ATTR_UNDERLINE:
+    state->pen.underline = val->number;
+    break;
+  case VTERM_ATTR_ITALIC:
+    state->pen.italic = val->boolean;
+    break;
+  case VTERM_ATTR_BLINK:
+    state->pen.blink = val->boolean;
+    break;
+  case VTERM_ATTR_REVERSE:
+    state->pen.reverse = val->boolean;
+    break;
+  case VTERM_ATTR_CONCEAL:
+    state->pen.conceal = val->boolean;
+    break;
+  case VTERM_ATTR_STRIKE:
+    state->pen.strike = val->boolean;
+    break;
+  case VTERM_ATTR_FONT:
+    state->pen.font = val->number;
+    break;
+  case VTERM_ATTR_FOREGROUND:
+    state->pen.fg = val->color;
+    break;
+  case VTERM_ATTR_BACKGROUND:
+    state->pen.bg = val->color;
+    break;
+  case VTERM_ATTR_SMALL:
+    state->pen.small = val->boolean;
+    break;
+  case VTERM_ATTR_BASELINE:
+    state->pen.baseline = val->number;
+    break;
+  case VTERM_ATTR_URI:
+    state->pen.uri = val->number;
+    break;
+  default:
+    return 0;
+  }
+
+  if(state->callbacks && state->callbacks->setpenattr)
+    (*state->callbacks->setpenattr)(attr, val, state->cbdata);
+
+  return 1;
+}
diff --git a/src/vterm/screen.c b/src/vterm/screen.c
index 720d1bb939..bd3cbd6bd0 100644
--- a/src/vterm/screen.c
+++ b/src/vterm/screen.c
@@ -17,6 +17,9 @@ typedef struct
   /* After the bitfield */
   VTermColor   fg, bg;
 
+  /* Opaque ID that maps to a URI in a set */
+  int uri;
+
   unsigned int bold      : 1;
   unsigned int underline : 2;
   unsigned int italic    : 1;
@@ -444,6 +447,9 @@ static int setpenattr(VTermAttr attr, VTermValue *val, void *user)
   case VTERM_ATTR_BASELINE:
     screen->pen.baseline = val->number;
     return 1;
+  case VTERM_ATTR_URI:
+    screen->pen.uri = val->number;
+    return 1;
 
   case VTERM_N_ATTRS:
     return 0;
@@ -705,6 +711,8 @@ static void resize_buffer(VTermScreen *screen, int bufidx, int new_rows, int new
         dst->pen.fg = src->fg;
         dst->pen.bg = src->bg;
 
+        dst->pen.uri = src->uri;
+
         if(src->width == 2 && pos.col < (new_cols-1))
           (dst + 1)->chars[0] = (uint32_t) -1;
       }
@@ -997,6 +1005,8 @@ int vterm_screen_get_cell(const VTermScreen *screen, VTermPos pos, VTermScreenCe
   cell->fg = intcell->pen.fg;
   cell->bg = intcell->pen.bg;
 
+  cell->uri = intcell->pen.uri;
+
   if(pos.col < (screen->cols - 1) &&
      getcell(screen, pos.row, pos.col + 1)->chars[0] == (uint32_t)-1)
     cell->width = 2;
@@ -1116,9 +1126,11 @@ static int attrs_differ(VTermAttrMask attrs, ScreenCell *a, ScreenCell *b)
     return 1;
   if((attrs & VTERM_ATTR_BACKGROUND_MASK) && !vterm_color_is_equal(&a->pen.bg, &b->pen.bg))
     return 1;
-  if((attrs & VTERM_ATTR_SMALL_MASK)    && (a->pen.small != b->pen.small))
+  if((attrs & VTERM_ATTR_SMALL_MASK)      && (a->pen.small != b->pen.small))
+    return 1;
+  if((attrs & VTERM_ATTR_BASELINE_MASK)   && (a->pen.baseline != b->pen.baseline))
     return 1;
-  if((attrs & VTERM_ATTR_BASELINE_MASK)    && (a->pen.baseline != b->pen.baseline))
+  if((attrs & VTERM_ATTR_URI_MASK)        && (a->pen.uri != b->pen.uri))
     return 1;
 
   return 0;
diff --git a/src/vterm/vterm.c b/src/vterm/vterm.c
index e1f676f5b6..870a61566e 100644
--- a/src/vterm/vterm.c
+++ b/src/vterm/vterm.c
@@ -278,6 +278,7 @@ VTermValueType vterm_get_attr_type(VTermAttr attr)
     case VTERM_ATTR_BACKGROUND: return VTERM_VALUETYPE_COLOR;
     case VTERM_ATTR_SMALL:      return VTERM_VALUETYPE_BOOL;
     case VTERM_ATTR_BASELINE:   return VTERM_VALUETYPE_INT;
+    case VTERM_ATTR_URI:        return VTERM_VALUETYPE_INT;
 
     case VTERM_N_ATTRS: return 0;
   }
diff --git a/src/vterm/vterm.h b/src/vterm/vterm.h
index 44e15023c0..929418c63a 100644
--- a/src/vterm/vterm.h
+++ b/src/vterm/vterm.h
@@ -245,6 +245,7 @@ typedef enum {
   VTERM_ATTR_BACKGROUND, // color:  40-49 100-107
   VTERM_ATTR_SMALL,      // bool:   73, 74, 75
   VTERM_ATTR_BASELINE,   // number: 73, 74, 75
+  VTERM_ATTR_URI,        // number
 
   VTERM_N_ATTRS
 } VTermAttr;
@@ -470,6 +471,7 @@ void vterm_state_set_default_colors(VTermState *state, const VTermColor *default
 void vterm_state_set_palette_color(VTermState *state, int index, const VTermColor *col);
 void vterm_state_set_bold_highbright(VTermState *state, int bold_is_highbright);
 int  vterm_state_get_penattr(const VTermState *state, VTermAttr attr, VTermValue *val);
+int  vterm_state_set_penattr(VTermState *state, VTermAttr attr, VTermValueType type, VTermValue *val);
 int  vterm_state_set_termprop(VTermState *state, VTermProp prop, VTermValue *val);
 void vterm_state_focus_in(VTermState *state);
 void vterm_state_focus_out(VTermState *state);
@@ -529,6 +531,7 @@ typedef struct {
   char     width;
   VTermScreenCellAttrs attrs;
   VTermColor fg, bg;
+  int uri;
 } VTermScreenCell;
 
 typedef struct {
@@ -589,8 +592,9 @@ typedef enum {
   VTERM_ATTR_CONCEAL_MASK    = 1 << 9,
   VTERM_ATTR_SMALL_MASK      = 1 << 10,
   VTERM_ATTR_BASELINE_MASK   = 1 << 11,
+  VTERM_ATTR_URI_MASK        = 1 << 12,
 
-  VTERM_ALL_ATTRS_MASK = (1 << 12) - 1
+  VTERM_ALL_ATTRS_MASK = (1 << 13) - 1
 } VTermAttrMask;
 
 int vterm_screen_get_attrs_extent(const VTermScreen *screen, VTermRect *extent, VTermPos pos, VTermAttrMask attrs);
diff --git a/src/vterm/vterm_internal.h b/src/vterm/vterm_internal.h
index e79d74be6f..53f9b5e100 100644
--- a/src/vterm/vterm_internal.h
+++ b/src/vterm/vterm_internal.h
@@ -40,6 +40,7 @@ struct VTermPen
 {
   VTermColor fg;
   VTermColor bg;
+  int uri;
   unsigned int bold:1;
   unsigned int underline:2;
   unsigned int italic:1;
diff --git a/test/functional/terminal/highlight_spec.lua b/test/functional/terminal/highlight_spec.lua
index 4f3d010d02..ca41cbf4a2 100644
--- a/test/functional/terminal/highlight_spec.lua
+++ b/test/functional/terminal/highlight_spec.lua
@@ -380,3 +380,23 @@ describe(':terminal highlight with custom palette', function()
     ]])
   end)
 end)
+
+describe(':terminal', function()
+  before_each(clear)
+
+  it('can display URLs', function()
+    local screen = Screen.new(50, 7)
+    screen:add_extra_attr_ids {
+      [100] = { url = 'https://example.com' },
+    }
+    screen:attach()
+    local chan = api.nvim_open_term(0, {})
+    api.nvim_chan_send(chan, '\027]8;;https://example.com\027\\Example\027]8;;\027\\')
+    screen:expect({
+      grid = [[
+        {100:^Example}                                           |
+                                                          |*6
+      ]],
+    })
+  end)
+end)