Add strstarts() helper function

nodename_from_path() in flattree.c uses strneq() to test that one
string starts with another. This is, in fact, the only correct usage
of strneq() in the entire tree.  To make things harder to confuse, add
a strstarts() function for this purpose.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

2 files changed, 2 insertions, 1 deletions

diff --git a/dtc.h b/dtc.h
index 760f9e3..bb0b91b 100644
--- a/dtc.h
+++ b/dtc.h
@@ -68,6 +68,7 @@ typedef uint32_t cell_t;
 
 #define streq(a, b)	(strcmp((a), (b)) == 0)
 #define strneq(a, b, n)	(strncmp((a), (b), (n)) == 0)
+#define strstarts(s, prefix)	(strncmp((s), (prefix), strlen(prefix)) == 0)
 
 #define ALIGN(x, a)	(((x) + (a) - 1) & ~((a) - 1))
 
diff --git a/flattree.c b/flattree.c
index fcf7154..8d268fb 100644
--- a/flattree.c
+++ b/flattree.c
@@ -731,7 +731,7 @@ static char *nodename_from_path(const char *ppath, const char *cpath)
 
 	plen = strlen(ppath);
 
-	if (!strneq(ppath, cpath, plen))
+	if (!strstarts(cpath, ppath))
 		die("Path \"%s\" is not valid as a child of \"%s\"\n",
 		    cpath, ppath);