[PATCH v6 1/8] pkt-line: add packet_read_line_gently()

[Ben Peart <peartben@xxxxxxxxx>]

Add packet_read_line_gently() to enable reading a line without dying on
EOF.

Signed-off-by: Ben Peart <benpeart@xxxxxxxxxxxxx>
---
 pkt-line.c | 14 +++++++++++++-
 pkt-line.h | 10 ++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/pkt-line.c b/pkt-line.c
index d4b6bfe076..bfdb177b34 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -315,7 +315,7 @@ static char *packet_read_line_generic(int fd,
 			      PACKET_READ_CHOMP_NEWLINE);
 	if (dst_len)
 		*dst_len = len;
-	return len ? packet_buffer : NULL;
+	return (len > 0) ? packet_buffer : NULL;
 }
 
 char *packet_read_line(int fd, int *len_p)
@@ -323,6 +323,18 @@ char *packet_read_line(int fd, int *len_p)
 	return packet_read_line_generic(fd, NULL, NULL, len_p);
 }
 
+int packet_read_line_gently(int fd, int *dst_len, char** dst_line)
+{
+	int len = packet_read(fd, NULL, NULL,
+			      packet_buffer, sizeof(packet_buffer),
+			      PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
+	if (dst_len)
+		*dst_len = len;
+	if (dst_line)
+		*dst_line = (len > 0) ? packet_buffer : NULL;
+	return len;
+}
+
 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 {
 	return packet_read_line_generic(-1, src, src_len, dst_len);
diff --git a/pkt-line.h b/pkt-line.h
index 18eac64830..ad30db101a 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -74,6 +74,16 @@ int packet_read(int fd, char **src_buffer, size_t *src_len, char
 char *packet_read_line(int fd, int *size);
 
 /*
+ * Convenience wrapper for packet_read that sets the PACKET_READ_GENTLE_ON_EOF
+ * and CHOMP_NEWLINE options. The return value specifies the number of bytes
+ * read into the buffer or -1 on truncated input. If the *dst_line parameter
+ * is not NULL it will return NULL for a flush packet and otherwise points to
+ * a static buffer (that may be overwritten by subsequent calls). If the size
+ * parameter is not NULL, the length of the packet is written to it.
+ */
+int packet_read_line_gently(int fd, int *size, char** dst_line);
+
+/*
  * Same as packet_read_line, but read from a buf rather than a descriptor;
  * see packet_read for details on how src_* is used.
  */
-- 
2.12.0.windows.1.33.g243d9b384c