[musl] [PATCH libc-test v3] functional: add mntent test

[Alyssa Ross <hi@alyssa.is>]

This only checks reading an fstab from an stream.  I haven't written
tests for setmntent(), addmntent(), or hasmntnent().

test_getmntent exposes a bug in musl 1.2.3 where lines omitting the
final two fields, which are supposed to be optional according to
fstab(5), are not accepted.  It also exposes a current bug, where if
the numeric fields are omitted, the last field seen will have a
newline appended to its value.  The tests all pass on Glibc.
---
v3: updated description for current musl
v2: https://inbox.vuxu.org/musl/20210821085420.474615-3-hi@alyssa.is/

Previously I had a second, optional patch, that would have tested the 
behavior of a single-field mntent entry.  I've dropped that one, because
musl chose not to match Glibc in accepting it.

 AUTHORS                 |  1 +
 src/functional/mntent.c | 76 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 src/functional/mntent.c

diff --git a/AUTHORS b/AUTHORS
index ff99471..cf2a394 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -5,3 +5,4 @@ John Spencer
 Jens Gustedt
 Alexander Monakov
 Julien Ramseier
+Alyssa Ross
diff --git a/src/functional/mntent.c b/src/functional/mntent.c
new file mode 100644
index 0000000..59d816a
--- /dev/null
+++ b/src/functional/mntent.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: MIT
+
+#define _DEFAULT_SOURCE // for getmntent_r
+
+#include <mntent.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include "test.h"
+
+#define ASSERT(x) do {				 \
+		if (!(x)) {			 \
+			t_error(#x " failed\n"); \
+			exit(EXIT_FAILURE);	 \
+		}				 \
+	} while (0);
+
+#define ERR(fmt, ...) do {					       \
+		t_error(fmt ": %s\n", ##__VA_ARGS__, strerror(errno)); \
+		exit(EXIT_FAILURE);				       \
+	} while (0)
+
+void test_getmntent_empty(void)
+{
+	char fstab[] = "\n";
+	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
+	if (!f) ERR("fmemopen");
+	ASSERT(!getmntent(f));
+	ASSERT(endmntent(f) == 1);
+}
+
+void test_getmntent(void)
+{
+	// Checks that the fifth and sixth fields default to 0.
+	char fstab[] = "none /proc proc defaults\n";
+	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
+	if (!f) ERR("fmemopen");
+	struct mntent *m = getmntent(f);
+	ASSERT(m);
+	ASSERT(!strcmp(m->mnt_fsname, "none"));
+	ASSERT(!strcmp(m->mnt_dir, "/proc"));
+	ASSERT(!strcmp(m->mnt_type, "proc"));
+	ASSERT(!strcmp(m->mnt_opts, "defaults"));
+	ASSERT(m->mnt_freq == 0);
+	ASSERT(m->mnt_passno == 0);
+	ASSERT(endmntent(f) == 1);
+}
+
+void test_getmntent_r(void)
+{
+	struct mntent m, *r;
+	char fstab[] = "/dev/sda\t/\text4\trw,nosuid\t2\t1\n";
+	char buf[sizeof(fstab)];
+
+	FILE *f = fmemopen((void *)fstab, sizeof fstab - 1, "r");
+	if (!f) ERR("fmemopen");
+
+	r = getmntent_r(f, &m, buf, sizeof buf);
+	ASSERT(r == &m);
+	ASSERT(!strcmp(m.mnt_fsname, "/dev/sda"));
+	ASSERT(!strcmp(m.mnt_dir, "/"));
+	ASSERT(!strcmp(m.mnt_type, "ext4"));
+	ASSERT(!strcmp(m.mnt_opts, "rw,nosuid"));
+	ASSERT(m.mnt_freq == 2);
+	ASSERT(m.mnt_passno == 1);
+	ASSERT(endmntent(f) == 1);
+}
+
+int main(void)
+{
+	test_getmntent_empty();
+	test_getmntent();
+	test_getmntent_r();
+}

base-commit: a07fb60c4996955216ef9a331dae124374984b3a
-- 
2.46.0