CHUNKING: Fix flush of chunk on error

2 files changed, 9 insertions, 2 deletions

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 9404b7a57..4b3d64e0c 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -178,6 +178,10 @@ JH/30 Fix a logging bug on aarch64: an unsafe routine was previously used for
       connection in response to HELO" was logged instead of the actual 4xx
       error for the HELO.
 
+JH/31 Fix CHUNKING code to properly flush the unwanted chunk after an error.
+      Previously only that bufferd was discarded, resulting in SYMTP command
+      desynchronisation.
+
 
 Exim version 4.89
 -----------------
diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index b27949e35..1fdb705a5 100644
--- a/src/src/smtp_in.c
+++ b/src/src/smtp_in.c
@@ -681,8 +681,11 @@ return buf;
 void
 bdat_flush_data(void)
 {
-unsigned n = chunking_data_left;
-(void) bdat_getbuf(&n);
+while (chunking_data_left)
+{
+  unsigned n = chunking_data_left;
+  (void) bdat_getbuf(&n);
+}
 
 receive_getc = lwr_receive_getc;
 receive_getbuf = lwr_receive_getbuf;