From 8fbc8579f2481dc3eeb962e99522047291e16fbe Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Thu, 11 Feb 2021 06:51:21 -0500
Subject: [PATCH] Allow zone information to be omitted from timestamp strings

---
 include/qpdf/QUtil.hh | 5 +++--
 libqpdf/QUtil.cc      | 4 ++--
 libtests/qutil.cc     | 4 ++++
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/qpdf/QUtil.hh b/include/qpdf/QUtil.hh
index 09a6c181..5b1f8aae 100644
--- a/include/qpdf/QUtil.hh
+++ b/include/qpdf/QUtil.hh
@@ -203,8 +203,9 @@ namespace QUtil
 
     // Convert a QPDFTime structure to a PDF timestamp string, which
     // is "D:yyyymmddhhmmss<z>" where <z> is either "Z" for UTC or
-    // "-hh'mm'" or "+hh'mm'" for timezone offset. Examples:
-    // "D:20210207161528-05'00'", "D:20210207211528Z". See
+    // "-hh'mm'" or "+hh'mm'" for timezone offset. <z> may also be
+    // omitted. Examples: "D:20210207161528-05'00'",
+    // "D:20210207211528Z", "D:20210207211528". See
     // get_current_qpdf_time and the QPDFTime structure above.
     QPDF_DLL
     std::string qpdf_time_to_pdf_time(QPDFTime const&);
diff --git a/libqpdf/QUtil.cc b/libqpdf/QUtil.cc
index 39d21ea0..4b86c0d4 100644
--- a/libqpdf/QUtil.cc
+++ b/libqpdf/QUtil.cc
@@ -898,7 +898,7 @@ QUtil::pdf_time_to_qpdf_time(std::string const& str, QPDFTime* qtm)
 {
     static std::regex pdf_date("^D:([0-9]{4})([0-9]{2})([0-9]{2})"
                                "([0-9]{2})([0-9]{2})([0-9]{2})"
-                               "(?:(Z)|([\\+\\-])([0-9]{2})'([0-9]{2})')$");
+                               "(?:(Z?)|([\\+\\-])([0-9]{2})'([0-9]{2})')$");
     std::smatch m;
     if (! std::regex_match(str, m, pdf_date))
     {
@@ -909,7 +909,7 @@ QUtil::pdf_time_to_qpdf_time(std::string const& str, QPDFTime* qtm)
         return QUtil::string_to_int(s.c_str());
     };
 
-    if (m[7] == "")
+    if (m[8] != "")
     {
         tz_delta = ((to_i(m[9]) * 60) +
                     to_i(m[10]));
diff --git a/libtests/qutil.cc b/libtests/qutil.cc
index b67b7580..965c4352 100644
--- a/libtests/qutil.cc
+++ b/libtests/qutil.cc
@@ -594,6 +594,10 @@ void timestamp_test()
     check(QUtil::QPDFTime(2021, 2, 10, 1, 19, 25, -330));
     check(QUtil::QPDFTime(2021, 2, 9, 19, 19, 25, 0));
     assert(! QUtil::pdf_time_to_qpdf_time("potato"));
+    assert(QUtil::pdf_time_to_qpdf_time("D:20210211064743Z"));
+    assert(QUtil::pdf_time_to_qpdf_time("D:20210211064743-05'00'"));
+    assert(QUtil::pdf_time_to_qpdf_time("D:20210211064743+05'30'"));
+    assert(QUtil::pdf_time_to_qpdf_time("D:20210211064743"));
     // Round trip on the current time without actually printing it.
     // Manual testing was done to ensure that we are actually getting
     // back the current time in various timezones.