diff --git a/autofs-5.1.8-fix-minus-only-option-handling-in-concat_options.patch b/autofs-5.1.8-fix-minus-only-option-handling-in-concat_options.patch
new file mode 100644
index 0000000..717affd
--- /dev/null
+++ b/autofs-5.1.8-fix-minus-only-option-handling-in-concat_options.patch
@@ -0,0 +1,88 @@
+autofs-5.1.8 - fix minus only option handling in concat_options()
+
+From: Ian Kent <raven@themaw.net>
+
+While a '-' alone isn't strictly valid it hadn't previously cuased a
+parse error. So commit 9047e91ffa69 (autofs-5.1.7 - fix concat_options()
+error handling) introduced a regression by no longer allowing this.
+
+Fix this regression by only failing if errno is set to a non-zero value
+on return from concat_options() as well as returning NULL.
+
+Fixes: 9047e91ffa69 (autofs-5.1.7 - fix concat_options() error handling)
+Signed-off-by: Ian Kent <raven@themaw.net>
+---
+ CHANGELOG           |    1 +
+ modules/parse_sun.c |   25 +++++++++++++++++++------
+ 2 files changed, 20 insertions(+), 6 deletions(-)
+
+--- autofs-5.1.7.orig/CHANGELOG
++++ autofs-5.1.7/CHANGELOG
+@@ -110,6 +110,7 @@
+ - fix hosts map deadlock on restart.
+ - fix deadlock with hosts map reload.
+ - fix memory leak in update_hosts_mounts().
++- fix minus only option handling in concat_options().
+ 
+ 25/01/2021 autofs-5.1.7
+ - make bind mounts propagation slave by default.
+--- autofs-5.1.7.orig/modules/parse_sun.c
++++ autofs-5.1.7/modules/parse_sun.c
+@@ -376,10 +376,16 @@ static int do_init(int argc, const char
+ 	if (gbl_options) {
+ 		append_options = defaults_get_append_options();
+ 		if (append_options) {
+-			char *tmp = concat_options(gbl_options, ctxt->optstr);
++			char *tmp;
++
++			errno = 0;
++			tmp = concat_options(gbl_options, ctxt->optstr);
+ 			if (!tmp) {
+-				char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
+-				logerr(MODPREFIX "concat_options: %s", estr);
++				/* Ignore non-error NULL return */
++				if (errno) {
++					char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
++					logerr(MODPREFIX "concat_options: %s", estr);
++				}
+ 				/* freed in concat_options */
+ 				ctxt->optstr = NULL;
+ 			} else
+@@ -1007,9 +1013,12 @@ static int parse_mapent(const char *ent,
+ 				free(myoptions);
+ 				myoptions = newopt;
+ 			} else if (newopt) {
++				errno = 0;
+ 				tmp = concat_options(myoptions, newopt);
+-				if (!tmp) {
++				/* Ignore non-error NULL return */
++				if (!tmp && errno) {
+ 					char *estr;
++
+ 					estr = strerror_r(errno, buf, MAX_ERR_BUF);
+ 					error(logopt, MODPREFIX
+ 					      "concat_options: %s", estr);
+@@ -1381,8 +1390,10 @@ dont_expand:
+ 				free(mnt_options);
+ 				mnt_options = noptions;
+ 			} else if (noptions) {
++				errno = 0;
+ 				tmp = concat_options(mnt_options, noptions);
+-				if (!tmp) {
++				/* Ignore non-error NULL return */
++				if (!tmp && errno) {
+ 					char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
+ 					error(ap->logopt,
+ 					      MODPREFIX "concat_options: %s", estr);
+@@ -1406,8 +1417,10 @@ dont_expand:
+ 				free(options);
+ 				options = mnt_options;
+ 			} else if (mnt_options) {
++				errno = 0;
+ 				tmp = concat_options(options, mnt_options);
+-				if (!tmp) {
++				/* Ignore non-error NULL return */
++				if (!tmp && errno) {
+ 					char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
+ 					error(ap->logopt, MODPREFIX "concat_options: %s", estr);
+ 					free(pmapent);
diff --git a/autofs.spec b/autofs.spec
index 9cb05c8..cb8a80c 100644
--- a/autofs.spec
+++ b/autofs.spec
@@ -12,7 +12,7 @@
 Summary: A tool for automatically mounting and unmounting filesystems
 Name: autofs
 Version: 5.1.7
-Release: 34%{?dist}
+Release: 35%{?dist}
 Epoch: 1
 License: GPLv2+
 Source: https://www.kernel.org/pub/linux/daemons/autofs/v5/autofs-%{version}-2.tar.gz
@@ -136,6 +136,7 @@ Patch108: autofs-5.1.8-coverity-fix-for-invalid-access.patch
 Patch109: autofs-5.1.8-fix-hosts-map-deadlock-on-restart.patch
 Patch110: autofs-5.1.8-fix-deadlock-with-hosts-map-reload.patch
 Patch111: autofs-5.1.8-fix-memory-leak-in-update_hosts_mounts.patch
+Patch112: autofs-5.1.8-fix-minus-only-option-handling-in-concat_options.patch
 
 %if %{with_systemd}
 BuildRequires: systemd-units
@@ -316,6 +317,7 @@ echo %{version}-%{release} > .version
 %patch109 -p1
 %patch110 -p1
 %patch111 -p1
+%patch112 -p1
 
 %build
 LDFLAGS=-Wl,-z,now
@@ -424,6 +426,12 @@ fi
 %dir /etc/auto.master.d
 
 %changelog
+* Wed Nov 30 2022 Ian Kent <ikent@redhat.com> - 1:5.1.7-35
+- bz2145251 - RHEL9: automount does not handle null option string after
+  "-" anymore
+  - fix minus only option handling in concat_options().
+- Resolves: rhbz#2145251
+
 * Tue Nov 29 2022 Ian Kent <ikent@redhat.com> - 1:5.1.7-34
 - bz2147491 - segfault due to lookup_mod->context address being freed
   and reused while multiple threads were using it