From 2f8997d3ed1aa846233592d65e0778b54f3cb727 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Tue, 18 Apr 2017 12:02:21 -0400
Subject: [PATCH] Make parse fail if fmt string is not completely consumed.

---
 date.h                        |  5 ++---
 test/date_test/parse.pass.cpp | 13 +++++++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/date.h b/date.h
index d3f700c..2131246 100644
--- a/date.h
+++ b/date.h
@@ -5367,9 +5367,8 @@ read(std::basic_istream<CharT, Traits>& is, CharT a0, Args&& ...args)
     if (a0 != CharT{})
     {
         auto ic = is.peek();
-        if (Traits::eq_int_type(ic, Traits::eof()))
-            return;
-        if (!Traits::eq(Traits::to_char_type(ic), a0))
+        if (Traits::eq_int_type(ic, Traits::eof()) ||
+            !Traits::eq(Traits::to_char_type(ic), a0))
         {
             is.setstate(std::ios::failbit);
             return;
diff --git a/test/date_test/parse.pass.cpp b/test/date_test/parse.pass.cpp
index 89ff4b3..05b666d 100644
--- a/test/date_test/parse.pass.cpp
+++ b/test/date_test/parse.pass.cpp
@@ -716,6 +716,18 @@ test_Z()
     }
 }
 
+void
+test_trailing_Z()
+{
+    std::string format = "%FT%TZ";
+    std::string datetime = "2017-2-15T13:13:13";
+    std::istringstream input(datetime);
+    date::sys_seconds tp;
+    input >> date::parse(format, tp);
+    assert(input.fail());
+    assert(input.eof());
+}
+
 int
 main()
 {
@@ -743,4 +755,5 @@ main()
     test_X();
     test_z();
     test_Z();
+    test_trailing_Z();
 }