[coreboot-gerrit] Change in ...coreboot[master]: libpayload/libc: Correct strlcat return value

[Jacob Garber (Code Review)]

Jacob Garber has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/33787

Change subject: libpayload/libc: Correct strlcat return value
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libpayload/libc: Correct strlcat return value

The documented return value for strlcat is horribly wrong, as is the
return value itself. It should not return the number of appended bytes,
but rather the total size of the concatenated string. From the man page:

The strlcpy() and strlcat() functions return the total length of the
    string they tried to create.  For strlcpy() that means the length of
    src. For strlcat() that means the initial length of dst plus the
    length of src.  While this may seem somewhat confusing, it was done
    to make truncation detection simple.

Change-Id: I4421305af85bce88d12d6fdc2eea6807ccdcf449
Signed-off-by: Jacob Garber 
---
M payloads/libpayload/libc/string.c
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/87/33787/1

diff --git a/payloads/libpayload/libc/string.c b/payloads/libpayload/libc/string.c
index 6c257cb..bd795f4 100644
--- a/payloads/libpayload/libc/string.c
+++ b/payloads/libpayload/libc/string.c
@@ -249,7 +249,7 @@
  * @param d The destination string.
  * @param s The source string.
  * @param n d will have at most n-1 characters (plus NUL) after invocation.
- * @return A pointer to the destination string.
+ * @return The total length of the string that would have been created.
  */
 size_t strlcat(char *d, const char *s, size_t n)
 {
@@ -264,7 +264,7 @@
    	p[i] = s[i];

p[i] = '\0';
-	return max;
+	return sl + dl;
 }

/**