Fix problem parsing config files with Windows line endings.

Closes #2297. Thanks to all the people who commented there!

ChangeLog.txt

@@ -6,6 +6,7 @@ Broker:
 - Fix LWT messages not being delivered if `per_listener_settings` was set to
   true. Closes #2314.
 - Various fixes around inflight quota management. Closes #2306.
+- Fix problem parsing config files with Windows line endings. Closes #2297.
 
 
 2.0.12 - 2021-08-31

src/conf.c

@@ -757,6 +757,10 @@ static int config__read_file_core(struct mosquitto__config *config, bool reload,
 			}
 			while((*buf)[slen-1] == 10 || (*buf)[slen-1] == 13){
 				(*buf)[slen-1] = 0;
+				slen = strlen(*buf);
+				if(slen == 0){
+					continue;
+				}
 			}
 			token = strtok_r((*buf), " ", &saveptr);
 			if(token){

test/broker/01-connect-windows-line-endings.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+# Test whether config files with windows line endings are accepted.
+# This just connects anonymously - if the config file causes a failure, the
+# broker won't start so the connection would fail.
+
+from mosq_test_helper import *
+
+def write_config(filename, port):
+    with open(filename, 'w') as f:
+        f.write("listener %d\r\n" % (port))
+        f.write("allow_anonymous true\r\n")
+
+def do_test():
+    port = mosq_test.get_port()
+    conf_file = os.path.basename(__file__).replace('.py', '.conf')
+    write_config(conf_file, port)
+
+    broker = mosq_test.start_broker(filename=os.path.basename(__file__), use_conf=True, port=port)
+
+    try:
+        for proto_ver in [4, 5]:
+            rc = 1
+            keepalive = 10
+            connect_packet = mosq_test.gen_connect("connect-anon-test-%d" % (proto_ver), keepalive=keepalive, proto_ver=proto_ver)
+
+            if proto_ver == 5:
+                connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+            else:
+                connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+            sock = mosq_test.do_client_connect(connect_packet, connack_packet, port=port)
+            sock.close()
+            rc = 0
+    except mosq_test.TestError:
+        pass
+    finally:
+        os.remove(conf_file)
+        broker.terminate()
+        broker.wait()
+        (stdo, stde) = broker.communicate()
+        if rc:
+            print(stde.decode('utf-8'))
+            print("proto_ver=%d" % (proto_ver))
+            exit(rc)
+
+
+do_test()
+exit(0)

test/broker/Makefile

@@ -32,6 +32,7 @@ msg_sequence_test:
 	./01-connect-uname-or-anon.py
 	./01-connect-uname-password-denied-no-will.py
 	./01-connect-uname-password-denied.py
+	./01-connect-windows-line-endings.py
 	./01-connect-zero-length-id.py
 
 

test/broker/test.py

@@ -14,6 +14,7 @@ tests = [
     (1, './01-connect-uname-or-anon.py'),
     (1, './01-connect-uname-password-denied-no-will.py'),
     (1, './01-connect-uname-password-denied.py'),
+    (1, './01-connect-windows-line-endings.py'),
     (2, './01-connect-zero-length-id.py'),
 
     (1, './02-shared-qos0-v5.py'),