[PATCH v6 5/6] lib: membuff: fix readline not returning line in case of overflow

[Svyatoslav Ryhel]

From: Ion Agorria <ion at agorria.com>

If line overflows readline it will not be returned, fix this behavior,
make it optional and documented properly.

Signed-off-by: Ion Agorria <ion at agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
 boot/bootmeth_extlinux.c | 2 +-
 common/console.c         | 2 +-
 include/membuff.h        | 5 +++--
 lib/membuff.c            | 4 ++--
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/boot/bootmeth_extlinux.c b/boot/bootmeth_extlinux.c
index aa2a4591eb..ae0ad1d53e 100644
--- a/boot/bootmeth_extlinux.c
+++ b/boot/bootmeth_extlinux.c
@@ -82,7 +82,7 @@ static int extlinux_fill_info(struct bootflow *bflow)
 	log_debug("parsing bflow file size %x\n", bflow->size);
 	membuff_init(&mb, bflow->buf, bflow->size);
 	membuff_putraw(&mb, bflow->size, true, &data);
-	while (len = membuff_readline(&mb, line, sizeof(line) - 1, ' '), len) {
+	while (len = membuff_readline(&mb, line, sizeof(line) - 1, ' ', true), len) {
 		char *tok, *p = line;
 
 		tok = strsep(&p, " ");
diff --git a/common/console.c b/common/console.c
index e6d7ebe935..cad65891fc 100644
--- a/common/console.c
+++ b/common/console.c
@@ -848,7 +848,7 @@ int console_record_readline(char *str, int maxlen)
 		return -ENOSPC;
 
 	return membuff_readline((struct membuff *)&gd->console_out, str,
-				maxlen, '\0');
+				maxlen, '\0', false);
 }
 
 int console_record_avail(void)
diff --git a/include/membuff.h b/include/membuff.h
index 21051b0c54..4eba626ce1 100644
--- a/include/membuff.h
+++ b/include/membuff.h
@@ -192,10 +192,11 @@ int membuff_free(struct membuff *mb);
  * @mb: membuff to adjust
  * @str: Place to put the line
  * @maxlen: Maximum line length (excluding terminator)
+ * @must_fit: If true then str is empty if line doesn't fit
  * Return: number of bytes read (including terminator) if a line has been
- *	   read, 0 if nothing was there
+ *	   read, 0 if nothing was there or line didn't fit when must_fit is set
  */
-int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch);
+int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch, bool must_fit);
 
 /**
  * membuff_extend_by() - expand a membuff
diff --git a/lib/membuff.c b/lib/membuff.c
index 3c6c0ae125..b242a38ff1 100644
--- a/lib/membuff.c
+++ b/lib/membuff.c
@@ -287,7 +287,7 @@ int membuff_free(struct membuff *mb)
 			(mb->end - mb->start) - 1 - membuff_avail(mb);
 }
 
-int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch)
+int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch, bool must_fit)
 {
 	int len;  /* number of bytes read (!= string length) */
 	char *s, *end;
@@ -309,7 +309,7 @@ int membuff_readline(struct membuff *mb, char *str, int maxlen, int minch)
 	}
 
 	/* couldn't get the whole string */
-	if (!ok) {
+	if (!ok && must_fit) {
 		if (maxlen)
 			*orig = '\0';
 		return 0;
-- 
2.40.1