[PATCH v2 2/2] discover/grub2: Add the '-e' test support

[Klaus Heinrich Kiwi]

Grub2 allows a special-case of file test using the '-e' operator, where
the path can be empty, and the device existance is tested.
E.g.:
  if [ -e (md/md-boot) ]; then

Add the support for testing this condition.

This fixes the following RH CoreOS bug:
  https://bugzilla.redhat.com/show_bug.cgi?id=1915540

Signed-off-by: Klaus Heinrich Kiwi <klaus at linux.vnet.ibm.com>
---
 discover/grub2/builtins.c                 | 7 ++++++-
 test/parser/test-grub2-ubuntu-13_04-x86.c | 4 ++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/discover/grub2/builtins.c b/discover/grub2/builtins.c
index 31cbe0e..291bb03 100644
--- a/discover/grub2/builtins.c
+++ b/discover/grub2/builtins.c
@@ -245,6 +245,11 @@ static bool builtin_test_op_file(struct grub2_script *script, char op,
 		return false;
 
 	switch (op) {
+	case 'e':
+		/* -e: for grub, a special case is testing for the device
+		 * presence itself (e.g. allows null file). */
+		result = true;
+		break;
 	case 's':
 		/* -s: return true if file exists and has non-zero size */
 		result = !path ? false : statbuf.st_size > 0;
@@ -336,7 +341,7 @@ static bool builtin_test_op(struct grub2_script *script,
 			return strlen(a1) != 0;
 		}
 
-		if (!strcmp(op, "-s") || !strcmp(op, "-f")) {
+		if (!strcmp(op, "-s") || !strcmp(op, "-f") || !(strcmp(op, "-e"))) {
 			*consumed = 2;
 			return builtin_test_op_file(script, op[1], a1);
 		}
diff --git a/test/parser/test-grub2-ubuntu-13_04-x86.c b/test/parser/test-grub2-ubuntu-13_04-x86.c
index 2f9aefd..785781a 100644
--- a/test/parser/test-grub2-ubuntu-13_04-x86.c
+++ b/test/parser/test-grub2-ubuntu-13_04-x86.c
@@ -19,13 +19,13 @@ void run_test(struct parser_test *test)
 	check_unresolved_resource(opt->boot_image);
 	check_unresolved_resource(opt->initrd);
 	check_name(opt, "Kubuntu GNU/Linux");
-	check_args(opt, "root=UUID=29beca39-9181-4780-bbb2-ab5d4be59aaf ro quiet splash ");
+	check_args(opt, "root=UUID=29beca39-9181-4780-bbb2-ab5d4be59aaf ro quiet splash vt.handoff=7");
 
 	opt = get_boot_option(ctx, 1);
 	check_unresolved_resource(opt->boot_image);
 	check_unresolved_resource(opt->initrd);
 	check_name(opt, "Kubuntu GNU/Linux, with Linux 3.8.0-19-generic");
-	check_args(opt, "root=UUID=29beca39-9181-4780-bbb2-ab5d4be59aaf ro quiet splash ");
+	check_args(opt, "root=UUID=29beca39-9181-4780-bbb2-ab5d4be59aaf ro quiet splash vt.handoff=7");
 
 	opt = get_boot_option(ctx, 2);
 	check_name(opt, "Kubuntu GNU/Linux, with Linux 3.8.0-19-generic (recovery mode)");
-- 
2.17.1