color: add color_set helper for copying raw colors

To set up default colors, we sometimes strcpy() from the
default string literals into our color buffers. This isn't a
bug (assuming the destination is COLOR_MAXLEN bytes), but
makes it harder to audit the code for problematic strcpy
calls.

Let's introduce a color_set which copies under the
assumption that there are COLOR_MAXLEN bytes in the
destination (of course you can call it on a smaller buffer,
so this isn't providing a huge amount of safety, but it's
more convenient than calling xsnprintf yourself).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/color.h b/color.h
index 7fe77fb55e..e155d13f78 100644
--- a/color.h
+++ b/color.h
@@ -75,6 +75,13 @@ extern int color_stdout_is_tty;
 int git_color_config(const char *var, const char *value, void *cb);
 int git_color_default_config(const char *var, const char *value, void *cb);
 
+/*
+ * Set the color buffer (which must be COLOR_MAXLEN bytes)
+ * to the raw color bytes; this is useful for initializing
+ * default color variables.
+ */
+void color_set(char *dst, const char *color_bytes);
+
 int git_config_colorbool(const char *var, const char *value);
 int want_color(int var);
 int color_parse(const char *value, char *dst);