Incremental selection: fix skipping some nodes

The range from ts nodes are a little different than
neovim's nodes. They start at 0 and the end is exclusive.
For example, a nvim range (1, 3, 2, 4) is the equivalent to the ts
range (0, 2, 1, 4).

Since we may hit parent nodes that have the same range as its child,
we skip those till we find one that actually changes the selection
(since this is the relevant part for the user).

Fixes https://github.com/nvim-treesitter/nvim-treesitter/issues/232

1 files changed, 28 insertions, 25 deletions

diff --git a/lua/nvim-treesitter/incremental_selection.lua b/lua/nvim-treesitter/incremental_selection.lua
index d716584fe..e40cc13cc 100644
--- a/lua/nvim-treesitter/incremental_selection.lua
+++ b/lua/nvim-treesitter/incremental_selection.lua
@@ -16,25 +16,16 @@ function M.init_selection()
   ts_utils.update_selection(buf, node)
 end
 
--- moves 0-based node position by one character
-local function inclusive_pos_to_exclusive(row, col)
-  local line = vim.fn.getline(row + 1)
-
-  -- move by one character changes row?
-  if #line == col + 1  then
-    return row + 1, 0
-  else
-    return row, col + 1
-  end
-end
-
+--- Get a ts compatible range of the current visual selection.
+--
+-- The range of ts nodes start with 0 and the ending range is exclusive.
 local function visual_selection_range()
   local _, csrow, cscol, _ = unpack(vim.fn.getpos("'<"))
   local _, cerow, cecol, _ = unpack(vim.fn.getpos("'>"))
-  if csrow < cerow or (csrow == cerow  and cscol <= cecol) then
-    return csrow-1, cscol-1, inclusive_pos_to_exclusive(cerow-1, cecol-1)
+  if csrow < cerow or (csrow == cerow and cscol <= cecol) then
+    return csrow - 1, cscol - 1, cerow - 1, cecol
   else
-    return cerow-1, cecol-1, inclusive_pos_to_exclusive(csrow-1, cscol-1)
+    return cerow - 1, cecol - 1, csrow - 1, cscol
   end
 end
 
@@ -49,9 +40,9 @@ local function select_incremental(get_parent)
     local buf = api.nvim_get_current_buf()
     local nodes = selections[buf]
 
-    -- initialize incremental selection with current selection
+    local csrow, cscol, cerow, cecol = visual_selection_range()
+    -- Initialize incremental selection with current selection
     if not nodes or #nodes == 0 or not range_matches(nodes[#nodes]) then
-      local csrow, cscol, cerow, cecol = visual_selection_range()
       local root = parsers.get_parser().tree:root()
       local node = root:named_descendant_for_range(csrow, cscol, cerow, cecol)
       ts_utils.update_selection(buf, node)
@@ -63,15 +54,27 @@ local function select_incremental(get_parent)
       return
     end
 
-    local node = get_parent(nodes[#nodes])
-    if not node then return end
-
-    table.insert(selections[buf], node)
-    if node ~= nodes[#nodes] then
-      table.insert(nodes, node)
+    -- Find a node that changes the current selection.
+    local node = nodes[#nodes]
+    while true do
+      node = get_parent(node)
+      if not node then return end
+      local srow, scol, erow, ecol = node:range()
+      local same_range = (
+        srow == csrow
+        and scol == cscol
+        and erow == cerow
+        and ecol == cecol
+      )
+      if not same_range then
+        table.insert(selections[buf], node)
+        if node ~= nodes[#nodes] then
+          table.insert(nodes, node)
+        end
+        ts_utils.update_selection(buf, node)
+        return
+      end
     end
-
-    ts_utils.update_selection(buf, node)
   end
 end