Refuse to start if we detect libevent 1.[12]

memcached.c

@@ -2374,6 +2374,7 @@ static void server_stats(ADD_STAT add_stats, conn *c) {
     APPEND_STAT("uptime", "%u", now);
     APPEND_STAT("time", "%ld", now + (long)process_started);
     APPEND_STAT("version", "%s", VERSION);
+    APPEND_STAT("libevent", "%s", event_get_version());
     APPEND_STAT("pointer_size", "%d", (int)(8 * sizeof(void *)));
 
 #ifndef WIN32
@@ -4250,6 +4251,28 @@ static int enable_large_pages(void) {
 #endif
 }
 
+/**
+ * Do basic sanity check of the runtime environment
+ * @return true if no errors found, false if we can't use this env
+ */
+static bool sanitycheck(void) {
+    /* One of our biggest problems is old and bogus libevents */
+    const char *ever = event_get_version();
+    if (ever != NULL) {
+        if (strncmp(ever, "1.", 2) == 0) {
+            /* Require at least 1.3 (that's still a couple of years old) */
+            if ((ever[2] == '1' || ever[2] == '2') && !isdigit(ever[3])) {
+                fprintf(stderr, "You are using libevent %s.\nPlease upgrade to"
+                        " a more recent version (1.3 or newer)\n",
+                        event_get_version());
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
 int main (int argc, char **argv) {
     int c;
     bool lock_memory = false;
@@ -4271,6 +4294,10 @@ int main (int argc, char **argv) {
     bool tcp_specified = false;
     bool udp_specified = false;
 
+    if (!sanitycheck()) {
+        return EX_OSERR;
+    }
+
     /* handle SIGINT */
     signal(SIGINT, sig_handler);
 

t/binary.t

@@ -2,7 +2,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 3361;
+use Test::More tests => 3373;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;

t/stats.t

@@ -16,6 +16,7 @@ my $sock = $server->sock;
 ## STAT uptime 13
 ## STAT time 1259170891
 ## STAT version 1.4.3
+## STAT libevent 1.4.13-stable.
 ## STAT pointer_size 32
 ## STAT rusage_user 0.001198
 ## STAT rusage_system 0.003523
@@ -57,7 +58,7 @@ my $sock = $server->sock;
 my $stats = mem_stats($sock);
 
 # Test number of keys
-is(scalar(keys(%$stats)), 38, "38 stats values");
+is(scalar(keys(%$stats)), 39, "39 stats values");
 
 # Test initial state
 foreach my $key (qw(curr_items total_items bytes cmd_get cmd_set get_hits evictions get_misses