git: 0a82cd4f101c - main - calendar: correct the search order for files

The branch main has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=0a82cd4f101c5eb8533a0049aaa3f06f005cf8af

commit 0a82cd4f101c5eb8533a0049aaa3f06f005cf8af
Author:     Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2023-12-18 05:53:03 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2023-12-18 05:53:51 +0000

    calendar: correct the search order for files
    
    Include files that don't begin with a '/' are documented to search the
    current directory, then /usr/share/calendar.  This hasn't been accurate
    for years, since e061f95e7b9b ("Rework calendar(1) parser") rewrote a
    lot of this.
    
    Stash off the cwd before we do any chdir()ing around and use that to
    honor the same order we'll follow for the -f flag.  This may result in
    an extra lookup that will fail for the initial calendar file, but I
    don't think it's worth the complexity to avoid it.
    
    While we're here, fix the documentation to just reference the order
    described in FILES so that we only need to keep it up to date in one
    place.
    
    Reviewed by:    bapt
    Sponsored by:   Klara, Inc.
    Differential Revision:  https://reviews.freebsd.org/D42278
---
 usr.bin/calendar/calendar.1 |  7 +++----
 usr.bin/calendar/io.c       | 31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/usr.bin/calendar/calendar.1 b/usr.bin/calendar/calendar.1
index af368475e4d5..edb3aca48c92 100644
--- a/usr.bin/calendar/calendar.1
+++ b/usr.bin/calendar/calendar.1
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd July 31, 2022
+.Dd December 17, 2023
 .Dt CALENDAR 1
 .Os
 .Sh NAME
@@ -213,9 +213,8 @@ succeeding lines.
 .Pp
 If the shared file is not referenced by a full pathname,
 .Nm
-searches in the current (or home) directory first, and then in the
-directory
-.Pa /usr/share/calendar .
+searches in the same order of precedence described in
+.Sx FILES .
 .Pp
 Blank lines and text protected by the C comment syntax
 .Ql /* ... */
diff --git a/usr.bin/calendar/io.c b/usr.bin/calendar/io.c
index 978027895dfe..17cd5b852c09 100644
--- a/usr.bin/calendar/io.c
+++ b/usr.bin/calendar/io.c
@@ -35,6 +35,7 @@
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <libutil.h>
 #include <locale.h>
 #include <pwd.h>
@@ -102,9 +103,11 @@ trimlr(char **buf)
 static FILE *
 cal_fopen(const char *file)
 {
+	static int cwdfd = -1;
 	FILE *fp;
 	char *home = getenv("HOME");
 	unsigned int i;
+	int fd;
 	struct stat sb;
 	static bool warned = false;
 	static char calendarhome[MAXPATHLEN];
@@ -114,6 +117,34 @@ cal_fopen(const char *file)
 		return (NULL);
 	}
 
+	/*
+	 * On -a runs, we would have done a chdir() earlier on, but we also
+	 * shouldn't have used the initial cwd anyways lest we bring
+	 * unpredictable behavior upon us.
+	 */
+	if (!doall && cwdfd == -1) {
+		cwdfd = open(".", O_DIRECTORY | O_PATH);
+		if (cwdfd == -1)
+			err(1, "open(cwd)");
+	}
+
+	/*
+	 * Check $PWD first as documented.
+	 */
+	if (cwdfd != -1) {
+		if ((fd = openat(cwdfd, file, O_RDONLY)) != -1) {
+			if ((fp = fdopen(fd, "r")) == NULL)
+				err(1, "fdopen(%s)", file);
+
+			cal_home = NULL;
+			cal_dir = NULL;
+			cal_file = file;
+			return (fp);
+		} else if (errno != ENOENT && errno != ENAMETOOLONG) {
+			err(1, "open(%s)", file);
+		}
+	}
+
 	if (chdir(home) != 0) {
 		warnx("Cannot enter home directory \"%s\"", home);
 		return (NULL);