core: fix ascii auth bug with missing newlines

If a user supplies an authfile to -Y with a single user:pass and no
newline, we were cutting the final character of the password and failing
to authenticate.

authfile.c

@@ -41,10 +41,13 @@ enum authfile_ret authfile_load(const char *file) {
         return AUTHFILE_STATFAIL;
     }
 
-    auth_data = calloc(1, sb.st_size + 1);
+    auth_data = calloc(1, sb.st_size + 2);
 
     char *auth_cur = auth_data;
-    char *auth_end = auth_data + sb.st_size;
+    // fgets will stop at EOF or a newline, reading at most one bytes less
+    // than the size limit. If a user supplies a file without an ending
+    // newline we will end up chopping the last character of the password.
+    char *auth_end = auth_data + sb.st_size + 1;
     auth_t *entry_cur = auth_entries;
     int used = 0;
 

t/ascii-auth2.t

@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+# Testing for single-line authfiles with no newline at the end.
+
+use strict;
+use Test::More tests => 4;
+use FindBin qw($Bin);
+use lib "$Bin/lib";
+use MemcachedTest;
+
+my $server = new_memcached("-Y $Bin/authfile2 -U 0");
+my $sock = $server->sock;
+
+# Fail to authenticate.
+print $sock "set foo 0 0 7\r\nfoo bab\r\n";
+like(scalar <$sock>, qr/CLIENT_ERROR/, "failed to authenticate");
+
+# Try for real.
+print $sock "set foo 0 0 7\r\nfoo bar\r\n";
+like(scalar <$sock>, qr/STORED/, "authenticated?");
+
+print $sock "set toast 0 0 2\r\nhi\r\n";
+like(scalar <$sock>, qr/STORED/, "stored an item that didn't look like user/pass");
+
+mem_get_is($sock, "toast", "hi");
+

t/authfile2

@@ -0,0 +1 @@
+foo:bar

t/whitespace.t

@@ -20,6 +20,7 @@ BEGIN {
     push(@exempted, glob("*.orig"));
     push(@exempted, glob(".*.swp"));
     push(@exempted, glob("queue.h"));
+    push(@exempted, glob("t/authfile2"));
     my %exempted_hash = map { $_ => 1 } @exempted;
 
     my @stuff = split /\0/, `git ls-files -z -c -m -o --exclude-standard`;