[PATCH v3 4/5] lib: membuff: fix readline not returning line in case of overflow

[Svyatoslav Ryhel]

From: Ion Agorria <i...@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 <i...@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamo...@gmail.com>
Reviewed-by: Mattijs Korpershoek <mkorpersh...@baylibre.com>
---
 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 8a869b137e..cd56035171 100644
--- a/common/console.c
+++ b/common/console.c
@@ -846,7 +846,7 @@ bool console_record_overflow(void)
 int console_record_readline(char *str, int maxlen)
 {
        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 36dc43a523..964e504d5b 100644
--- a/lib/membuff.c
+++ b/lib/membuff.c
@@ -288,7 +288,7 @@ 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;
@@ -310,7 +310,7 @@ 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