From: Karel Zak <kzak@redhat.com>
Date: Mon, 7 Sep 2020 09:52:13 +0000 (+0200)
Subject: libsmartcols: don't print empty output on empty table in JSON
X-Git-Tag: v2.37-rc1~495
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f29a2cfbe18ecc165f188b2df572be01a74e1ec5;p=thirdparty%2Futil-linux.git

libsmartcols: don't print empty output on empty table in JSON

old version:
 $ findmnt --json --type foo
 $

new version:
 $ findmnt --json --type foo
 {
    "filesystems": [
    ]
 }

Addresses: https://github.com/karelzak/util-linux/issues/1136
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libsmartcols/src/print-api.c b/libsmartcols/src/print-api.c
index 48b954baf3..9a9f2df942 100644
--- a/libsmartcols/src/print-api.c
+++ b/libsmartcols/src/print-api.c
@@ -116,7 +116,10 @@ static int do_print_table(struct libscols_table *tb, int *is_empty)
 	}
 	if (list_empty(&tb->tb_lines)) {
 		DBG(TAB, ul_debugobj(tb, "ignore -- no lines"));
-		if (is_empty)
+		if (scols_table_is_json(tb)) {
+			fput_table_open(tb);
+			fput_table_close(tb);
+		} else if (is_empty)
 			*is_empty = 1;
 		return 0;
 	}