sd-json,tree-wide: add sd_json_format_enabled() and use it everwhere

We often used a pattern like if (!FLAGS_SET(flags, SD_JSON_FORMAT_OFF)),
which is rather verbose and also contains a double negative, which we try
to avoid. Add a little helper to avoid an explicit bit check.

This change clarifies an aditional thing: in some cases we treated
SD_JSON_FORMAT_OFF as a flag (flags & SD_JSON_FORMAT_OFF), while in other cases
we treated it as an independent enum value (flags == SD_JSON_FORMAT_OFF).
In the first form, flags like SD_JSON_FORMAT_SSE do _not_ turn the json
output on, while in the second form they do. Let's use the first form
everywhere.

No functional change intended.

Initially I wasn't sure if this helper should be made public or just internal,
but it seems such a common pattern that if we expose the flags, we might just
as well expose it too, to make life easier for any consumers.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/home/homectl.c b/src/home/homectl.c
index 11270d7edb..b3aacbcbcf 100644
--- a/src/home/homectl.c
+++ b/src/home/homectl.c
@@ -203,7 +203,7 @@ static int list_homes(int argc, char *argv[], void *userdata) {
         if (r < 0)
                 return bus_log_parse_error(r);
 
-        if (!table_isempty(table) || !FLAGS_SET(arg_json_format_flags, SD_JSON_FORMAT_OFF)) {
+        if (!table_isempty(table) || sd_json_format_enabled(arg_json_format_flags)) {
                 r = table_set_sort(table, (size_t) 0);
                 if (r < 0)
                         return table_log_sort_error(r);
@@ -213,7 +213,7 @@ static int list_homes(int argc, char *argv[], void *userdata) {
                         return r;
         }
 
-        if (arg_legend && FLAGS_SET(arg_json_format_flags, SD_JSON_FORMAT_OFF)) {
+        if (arg_legend && !sd_json_format_enabled(arg_json_format_flags)) {
                 if (table_isempty(table))
                         printf("No home areas.\n");
                 else
@@ -671,7 +671,7 @@ static void dump_home_record(UserRecord *hr) {
                 log_warning("Warning: lacking rights to acquire privileged fields of user record of '%s', output incomplete.", hr->user_name);
         }
 
-        if (arg_json_format_flags & SD_JSON_FORMAT_OFF)
+        if (!sd_json_format_enabled(arg_json_format_flags))
                 user_record_show(hr, true);
         else {
                 _cleanup_(user_record_unrefp) UserRecord *stripped = NULL;