isync: Fix "Buffer too small" error

pkgs/tools/networking/isync/0001-Increase-imap_vprintf-buffer-size.patch

@@ -0,0 +1,34 @@
+From e8a3a20aed135272a9ec0103f4055411c075f043 Mon Sep 17 00:00:00 2001
+From: Michal Sojka <michal.sojka@cvut.cz>
+Date: Mon, 7 Nov 2022 00:07:22 +0100
+Subject: [PATCH] Increase imap_vprintf buffer size
+
+This fixes "Fatal: buffer too small. Please report a bug." error. See
+https://sourceforge.net/p/isync/mailman/isync-devel/thread/87fsevvebj.fsf%40steelpick.2x.cz/#msg37731590
+for related discussion.
+
+When using mbsync with XOAUTH2 authentication (needed for Office365
+mailboxes), the access token used for the LOGIN command may not fit
+into the currently used buffer of 1000 characters. In my case, I need
+the buffer to be at least 2000 characters long. To make this more
+future-proof, I increase the buffer size to 4000 characters.
+---
+ src/drv_imap.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/drv_imap.c b/src/drv_imap.c
+index c5a7aed..7847192 100644
+--- a/src/drv_imap.c
++++ b/src/drv_imap.c
+@@ -528,7 +528,7 @@ imap_vprintf( const char *fmt, va_list ap )
+ 	uint totlen = 0;
+ 	const char *segs[MAX_SEGS];
+ 	uint segls[MAX_SEGS];
+-	char buf[1000];
++	char buf[4000];
+ 
+ 	d = buf;
+ 	ed = d + sizeof(buf);
+-- 
+2.38.1
+

pkgs/tools/networking/isync/default.nix

@@ -12,6 +12,11 @@ stdenv.mkDerivation rec {
     sha256 = "1zq0wwvmqsl9y71546dr0aygzn9gjjfiw19hlcq87s929y4p6ckw";
   };
 
+  patches = [
+    # Fixes "Fatal: buffer too small" error
+    ./0001-Increase-imap_vprintf-buffer-size.patch
+  ];
+
   nativeBuildInputs = [ pkg-config perl ];
   buildInputs = [ openssl db cyrus_sasl zlib ]
     ++ lib.optionals stdenv.isDarwin [ Security ];