Change in flashrom[master]: helpers.c: optimize strndup

[Xiang Wang (Code Review)]

Xiang Wang has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/49741 )

Change subject: helpers.c: optimize strndup
......................................................................

helpers.c: optimize strndup

strndup is relative to strdup to prevent improper pointers from being
passed in, so that the function has no feedback for a long time. But
the old code used strlen in strndup. strlen may also have no feedback
for a long time. This patch solves this problem.

Change-Id: Id34127024085879228626fbad59af03268ec5255
Signed-off-by: Xiang Wang 
---
M helpers.c
1 file changed, 9 insertions(+), 8 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/41/49741/1

diff --git a/helpers.c b/helpers.c
index c83cd2c..289848d 100644
--- a/helpers.c
+++ b/helpers.c
@@ -106,15 +106,16 @@
 /* strndup is a POSIX function not present in MinGW */
 char *strndup(const char *src, size_t maxlen)
 {
-	if (strlen(src) > maxlen) {
-		char *retbuf;
-		if ((retbuf = malloc(1 + maxlen)) != NULL) {
-			memcpy(retbuf, src, maxlen);
-			retbuf[maxlen] = '\0';
-		}
-		return retbuf;
+	char *retbuf;
+	size_t len;
+	for (len = 0; len < maxlen; len++)
+		if (src[len] == '\0')
+			break;
+	if ((retbuf = malloc(1 + len)) != NULL) {
+		memcpy(retbuf, src, len);
+		retbuf[len] = '\0';
    }
-	return strdup(src);
+	return retbuf;
 }
 #endif