[PATCH v2 3/4] grep: copy struct in one fell swoop

["Martin Ågren" <martin.agren@gmail.com>]

We have a `struct grep_opt` with our defaults which we then copy into
the caller's struct. Rather than zeroing the target struct and copying
each element one by one, just copy everything at once. This leaves the
code simpler and more maintainable.

We don't have any ownership issues with what we're copying now and can
just greedily copy the whole thing. If and when we do need to handle
such elements (`char *`?), we must and can handle it appropriately. This
commit doesn't really change that.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
 grep.c | 25 ++-----------------------
 1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/grep.c b/grep.c
index 8f2009ec9f..7d740452cd 100644
--- a/grep.c
+++ b/grep.c
@@ -66,11 +66,6 @@ static const char *color_grep_slots[] = {
 	[GREP_COLOR_SEP]	    = "separator",
 };
 
-static void color_set(char *dst, const char *color_bytes)
-{
-	xsnprintf(dst, COLOR_MAXLEN, "%s", color_bytes);
-}
-
 static int parse_pattern_type_arg(const char *opt, const char *arg)
 {
 	if (!strcmp(arg, "default"))
@@ -157,9 +152,6 @@ int grep_config(const char *var, const char *value, void *cb)
  */
 void grep_init(struct grep_opt *opt, struct repository *repo, const char *prefix)
 {
-	struct grep_opt *def = &grep_defaults;
-	int i;
-
 #if defined(USE_LIBPCRE2)
 	if (!pcre2_global_context)
 		pcre2_global_context = pcre2_general_context_create(
@@ -171,26 +163,13 @@ void grep_init(struct grep_opt *opt, struct repository *repo, const char *prefix
 	pcre_free = free;
 #endif
 
-	memset(opt, 0, sizeof(*opt));
+	*opt = grep_defaults;
+
 	opt->repo = repo;
 	opt->prefix = prefix;
 	opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 	opt->pattern_tail = &opt->pattern_list;
 	opt->header_tail = &opt->header_list;
-
-	opt->only_matching = def->only_matching;
-	opt->color = def->color;
-	opt->extended_regexp_option = def->extended_regexp_option;
-	opt->pattern_type_option = def->pattern_type_option;
-	opt->linenum = def->linenum;
-	opt->columnnum = def->columnnum;
-	opt->max_depth = def->max_depth;
-	opt->pathname = def->pathname;
-	opt->relative = def->relative;
-	opt->output = def->output;
-
-	for (i = 0; i < NR_GREP_COLORS; i++)
-		color_set(opt->colors[i], def->colors[i]);
 }
 
 void grep_destroy(void)
-- 
2.29.2.454.gaff20da3a2