From f7e633069283ab18dffd8821c6049d04f896c2e5 Mon Sep 17 00:00:00 2001
From: Zeroes1 <Zeroes1@gmail.com>
Date: Tue, 21 Jul 2026 18:38:48 +0300
Subject: [PATCH] editor: eliminate brief [Loading...] flash on file open under
 Windows

---
 actions.go      |  1 +
 async_buffer.go | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/actions.go b/actions.go
index 7090ef5..0f3cdd3 100644
--- a/actions.go
+++ b/actions.go
@@ -367,6 +367,7 @@ func showEditor(pf *PanelsFrame, v vfs.VFS, path string, f vfs.ReadAtCloser) {
 
 	if f != nil {
 		buf = NewAsyncBuffer(context.Background(), f)
+		buf.prewarm()
 		pt = piecetable.NewWithBuffer(buf)
 	} else {
 		pt = piecetable.New(nil)
diff --git a/async_buffer.go b/async_buffer.go
index a4e2242..618df01 100644
--- a/async_buffer.go
+++ b/async_buffer.go
@@ -45,6 +45,28 @@ func (b *AsyncBuffer) Size() int {
 	return b.size
 }
 
+// Prewarm synchronously loads the first chunk so the first render
+// never sees ErrLoading, avoiding a brief [Loading...] flash.
+func (b *AsyncBuffer) prewarm() {
+	if b.size == 0 {
+		return
+	}
+	sz := b.chunkSize
+	if sz > b.size {
+		sz = b.size
+	}
+	data := make([]byte, sz)
+	n, err := b.file.ReadAt(b.ctx, data, 0)
+	if b.ctx.Err() != nil {
+		return
+	}
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if err == nil || err == io.EOF {
+		b.loaded[0] = data[:n]
+	}
+}
+
 func (b *AsyncBuffer) Read(offset, length int) ([]byte, error) {
 	if offset < 0 || offset >= b.size || length <= 0 {
 		return nil, nil