Be more careful when parsing times with timezones.

Consider the timezone abbreviation "IST" for Asia/Kolkata.
Unfortuately, the PHP strtotime() function, when it encounters
a timezone abbreviation, uses the first matching timezone
definition in the timezone database, which for IST is
Asia/Jerusalem!, rather than preferring the timezone that equals
the current timezone, if there is one.

And abbreviations like GMT-5 (for Etc/GMT-5) aren't even parsed.

Work around this with regular expressions.

Reported by Aakash Sharma.

log.php

@@ -94,8 +94,8 @@
 if ($_REQUEST["date"] == "")
     $_REQUEST["date"] = "now";
 if ($_REQUEST["date"] != "now" && isset($_REQUEST["search"]))
-    if (($firstDate = strtotime($_REQUEST["date"])) === false) {
-	$Conf->errorMsg("\"" . htmlspecialchars($_REQUEST["date"]) . "\" is not a valid date.");
+    if (($firstDate = $Conf->parse_time($_REQUEST["date"])) === false) {
+	$Conf->errorMsg("“" . htmlspecialchars($_REQUEST["date"]) . "” is not a valid date.");
 	$Eclass["date"] = " error";
     }
 

settings.php

@@ -208,7 +208,7 @@ function parseValue($name, $type) {
     else if ($type === "date" || $type === "cdate") {
 	if ($v == "" || strtoupper($v) == "N/A" || $v == "0")
 	    return -1;
-	else if (($v = strtotime($v)) !== false)
+	else if (($v = $Conf->parse_time($v)) !== false)
 	    return $v;
 	else
 	    $err = $SettingText[$name] . ": invalid date.";

src/conference.php

@@ -642,6 +642,29 @@ function parseableTime($value, $include_zone) {
         }
         return $d;
     }
+    function parse_time($d, $reference = null) {
+        global $Now, $Opt;
+        if ($reference === null)
+            $reference = $Now;
+        if (!isset($Opt["dateFormatTimezoneRemover"])
+            && function_exists("timezone_abbreviations_list")) {
+            $mytz = date_default_timezone_get();
+            $x = array();
+            foreach (timezone_abbreviations_list() as $tzname => $tzinfo) {
+                foreach ($tzinfo as $tz)
+                    if ($tz["timezone_id"] == $mytz)
+                        $x[] = preg_quote($tzname);
+            }
+            if (count($x) == 0)
+                $x[] = preg_quote(date("T", $reference));
+            $Opt["dateFormatTimezoneRemover"] =
+                "/(?:\\s|\\A)(?:" . join("|", $x) . ")(?:\\s|\\z)/i";
+        }
+        if (@$Opt["dateFormatTimezoneRemover"])
+            $d = preg_replace($Opt["dateFormatTimezoneRemover"], " ", $d);
+        return strtotime($d, $reference);
+    }
+
     function _printableTime($value, $long, $useradjust, $preadjust = null) {
 	global $Opt;
 	if ($value <= 0)

src/paperstatus.php

@@ -217,7 +217,7 @@ function normalize($pj, $old_pj) {
                 if (is_numeric($pj->$k))
                     $pj->$k = (int) $pj->$k;
                 else if (is_string($pj->$k))
-                    $pj->$k = strtotime($pj->$k, $Now);
+                    $pj->$k = $Conf->parse_time($pj->$k, $Now);
                 else
                     $pj->$k = false;
                 if ($pj->$k === false || $pj->$k < 0)