shada: Respect the optional buffer count for shada-%

Closes #5759

2 files changed, 17 insertions, 1 deletions

diff --git a/src/nvim/shada.c b/src/nvim/shada.c
index d902079739..34524580d7 100644
--- a/src/nvim/shada.c
+++ b/src/nvim/shada.c
@@ -2424,12 +2424,13 @@ static ShaDaWriteResult shada_write(ShaDaWriteDef *const sd_writer,
 
   // Write buffer list
   if (find_shada_parameter('%') != NULL) {
+    int max_bufs = get_shada_parameter('%');
     size_t buf_count = 0;
 #define IGNORE_BUF(buf)\
     (buf->b_ffname == NULL || !buf->b_p_bl || bt_quickfix(buf) \
      || in_bufset(&removable_bufs, buf))
     FOR_ALL_BUFFERS(buf) {
-      if (!IGNORE_BUF(buf)) {
+      if (!IGNORE_BUF(buf) && (max_bufs < 0 || buf_count < (size_t)max_bufs)) {
         buf_count++;
       }
     }
@@ -2450,6 +2451,9 @@ static ShaDaWriteResult shada_write(ShaDaWriteDef *const sd_writer,
       if (IGNORE_BUF(buf)) {
         continue;
       }
+      if (i >= buf_count) {
+        break;
+      }
       buflist_entry.data.buffer_list.buffers[i] = (struct buffer_list_buffer) {
         .pos = buf->b_last_cursor.mark,
         .fname = (char *) buf->b_ffname,
diff --git a/test/functional/shada/buffers_spec.lua b/test/functional/shada/buffers_spec.lua
index 01952560d6..7e6338897a 100644
--- a/test/functional/shada/buffers_spec.lua
+++ b/test/functional/shada/buffers_spec.lua
@@ -89,4 +89,16 @@ describe('ShaDa support code', function()
     eq(1, funcs.bufnr('$'))
     eq('', funcs.bufname(1))
   end)
+
+  it('restores 1 buffer with %1 in &shada, #5759', function()
+    set_additional_cmd('set shada+=%1')
+    reset()
+    nvim_command('edit ' .. testfilename)
+    nvim_command('edit ' .. testfilename_2)
+    nvim_command('qall')
+    reset()
+    eq(2, funcs.bufnr('$'))
+    eq('', funcs.bufname(1))
+    eq(testfilename, funcs.bufname(2))
+  end)
 end)