[PATCH 2/2] banned.h: mark strncpy as banned

[Jeff King <peff@peff.net>]

The strncpy() function is less horrible than strcpy(). But
it's still pretty easy to misuse because of its funny
termination semantics. And we already have a ready-made
alternative in strlcpy. So let's ban it, to make sure uses
don't creep in.

Note that there is one instance of strncpy in
compat/regex/regcomp.c. But this doesn't trigger the
ban-list even when compiling with NO_REGEX=1, because we
don't use git-compat-util.h when compiling it (instead we
rely on the system includes from the upstream library).

Since this use of strncpy was verified by manual inspection
and since it doesn't trigger the automated ban-list, we're
better off leaving it to keep our divergence from glibc
minimal.

Signed-off-by: Jeff King <peff@peff.net>
---
 banned.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/banned.h b/banned.h
index fe81020e0f..ae6aaaa4a9 100644
--- a/banned.h
+++ b/banned.h
@@ -11,6 +11,7 @@
 #define BANNED(func) sorry_##func##_is_a_banned_function()
 
 #define strcpy(x,y) BANNED(strcpy)
+#define strncpy(x,y,n) BANNED(strncpy)
 
 #ifdef HAVE_VARIADIC_MACROS
 #define sprintf(...) BANNED(sprintf)
-- 
2.18.0.540.g6c38643a7b