From 45a7e117eaa5e06c5dba27d20731af407b4b735b Mon Sep 17 00:00:00 2001
From: iamxvbaba <28732408+iamxvbaba@users.noreply.github.com>
Date: Thu, 30 Jul 2026 16:05:14 +0800
Subject: [PATCH] chore(giftfetch): sync NFT gift export fields

---
 cmd/giftfetch/main.go      | 13 +++++++------
 cmd/giftfetch/main_test.go | 17 +++++++++++++++++
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/cmd/giftfetch/main.go b/cmd/giftfetch/main.go
index 7736ab6e..bad96e32 100644
--- a/cmd/giftfetch/main.go
+++ b/cmd/giftfetch/main.go
@@ -830,12 +830,13 @@ func downloadPartSize(expectedSize int64) int {
 	if expectedSize <= 0 || expectedSize >= max {
 		return int(max)
 	}
-	// Choose a valid 4 KiB-aligned limit strictly larger than the file whenever
-	// possible, so downloader.Stream recognizes the first short chunk as final
-	// without an extra EOF probe.
-	partSize := ((expectedSize + 1 + unit - 1) / unit) * unit
-	if partSize > max {
-		partSize = max
+	// Non-precise upload.getFile limits must use the client-compatible chunk
+	// ladder (4, 8, ..., 512 KiB), whose values also divide a 1 MiB window.
+	// Merely rounding to an arbitrary 4 KiB multiple (for example 48 KiB)
+	// is rejected with LIMIT_INVALID by some official file DCs.
+	partSize := unit
+	for partSize <= expectedSize && partSize < max {
+		partSize *= 2
 	}
 	return int(partSize)
 }
diff --git a/cmd/giftfetch/main_test.go b/cmd/giftfetch/main_test.go
index 93233f80..da4a62c9 100644
--- a/cmd/giftfetch/main_test.go
+++ b/cmd/giftfetch/main_test.go
@@ -69,6 +69,7 @@ func TestDownloadPartSize(t *testing.T) {
 		{size: 1, want: 4 << 10},
 		{size: (4 << 10) - 1, want: 4 << 10},
 		{size: 4 << 10, want: 8 << 10},
+		{size: 48_632, want: 64 << 10},
 		{size: (512 << 10) - 1, want: 512 << 10},
 		{size: 512 << 10, want: 512 << 10},
 		{size: 1 << 20, want: 512 << 10},
@@ -80,6 +81,22 @@ func TestDownloadPartSize(t *testing.T) {
 	}
 }
 
+func TestDownloadPartSizeUsesNonPreciseChunkLadder(t *testing.T) {
+	const oneMiB = 1 << 20
+	for size := int64(1); size < 512<<10; size += 997 {
+		partSize := downloadPartSize(size)
+		if partSize < 4<<10 || partSize > 512<<10 || partSize%(4<<10) != 0 {
+			t.Fatalf("downloadPartSize(%d) = %d is outside the valid 4 KiB-aligned range", size, partSize)
+		}
+		if oneMiB%partSize != 0 {
+			t.Fatalf("downloadPartSize(%d) = %d does not divide a 1 MiB request window", size, partSize)
+		}
+		if int64(partSize) <= size {
+			t.Fatalf("downloadPartSize(%d) = %d does not cover the known-size single chunk", size, partSize)
+		}
+	}
+}
+
 func TestParseAllowedMissingThumbs(t *testing.T) {
 	allowed, err := parseAllowedMissingThumbs("5417911440709285239:photo:m,42:video:v")
 	if err != nil {