From 8979ebbdf221f51290fffbf941f7c517c2bf7ae0 Mon Sep 17 00:00:00 2001
From: Oswald Buddenhagen <ossi@users.sf.net>
Date: Tue, 1 Sep 2015 14:21:45 +0200
Subject: [PATCH] tolerate case changes in X-TUID header name

it is legal for an email system to simply change the case of rfc2822
headers, and at least one imap server apparently does just that.
this would lead to us not finding our own header, which is obviously not
helpful.

REFMAIL: CA+fD2U3hJEszmvwBsXEpTsaWgJ2Dh373mCESM3M0kg3ZwAYjaw@mail.gmail.com
---
 src/common.h   |  1 +
 src/drv_imap.c |  2 +-
 src/sync.c     |  2 +-
 src/util.c     | 16 ++++++++++++++++
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/common.h b/src/common.h
index 238af79..18390f3 100644
--- a/src/common.h
+++ b/src/common.h
@@ -116,6 +116,7 @@ void *memrchr( const void *s, int c, size_t n );
 #endif
 
 int starts_with( const char *str, int strl, const char *cmp, int cmpl );
+int starts_with_upper( const char *str, int strl, const char *cmp, int cmpl );
 int equals( const char *str, int strl, const char *cmp, int cmpl );
 
 #ifndef HAVE_TIMEGM
diff --git a/src/drv_imap.c b/src/drv_imap.c
index a0c13e0..608a2d3 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -967,7 +967,7 @@ parse_fetch_rsp( imap_store_t *ctx, list_t *list, char *s ATTR_UNUSED )
 					tmp = tmp->next;
 					if (!is_atom( tmp ))
 						goto bfail;
-					if (starts_with( tmp->val, tmp->len, "X-TUID: ", 8 ))
+					if (starts_with_upper( tmp->val, tmp->len, "X-TUID: ", 8 ))
 						tuid = tmp->val + 8;
 				} else {
 				  bfail:
diff --git a/src/sync.c b/src/sync.c
index eb444e0..4fb2026 100644
--- a/src/sync.c
+++ b/src/sync.c
@@ -338,7 +338,7 @@ msg_fetched( int sts, void *aux )
 					if (c == '\r')
 						lcrs++;
 					else if (c == '\n') {
-						if (starts_with( fmap + start, len - start, "X-TUID: ", 8 )) {
+						if (starts_with_upper( fmap + start, len - start, "X-TUID: ", 8 )) {
 							extra = (sbreak = start) - (ebreak = i);
 							goto oke;
 						}
diff --git a/src/util.c b/src/util.c
index 6851c6f..f05eec6 100644
--- a/src/util.c
+++ b/src/util.c
@@ -27,6 +27,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <string.h>
+#include <ctype.h>
 #include <pwd.h>
 
 static int need_nl;
@@ -241,6 +242,21 @@ starts_with( const char *str, int strl, const char *cmp, int cmpl )
 	return (strl >= cmpl) && !memcmp( str, cmp, cmpl );
 }
 
+int
+starts_with_upper( const char *str, int strl, const char *cmp, int cmpl )
+{
+	int i;
+
+	if (strl < 0)
+		strl = strnlen( str, cmpl + 1 );
+	if (strl < cmpl)
+		return 0;
+	for (i = 0; i < cmpl; i++)
+		if (str[i] != cmp[i] && toupper( str[i] ) != cmp[i])
+			return 0;
+	return 1;
+}
+
 int
 equals( const char *str, int strl, const char *cmp, int cmpl )
 {