Save Changes Bug 792106 - Wrong dates displayed

The first attempt to fix this, a17bc85a, doesn't work because the
boost::date_time constructor gets enough information in most cases to
generate a date, just not the one we expect. This change looks for '-' in
the fourth position and if it's there assumes iso-extended format, otherwise
it assumes delimiter-less ISO without the 'T', i.e. %Y%m%d%H%M%S.

libgnucash/engine/gnc-datetime.cpp

@@ -294,16 +294,12 @@ GncDateTimeImpl::GncDateTimeImpl(const std::string str) :
         auto input_facet(new Facet());
         std::istringstream ss(str.substr(0, tzpos));
         ss.imbue(std::locale(std::locale(), input_facet));
-        input_facet->set_iso_extended_format();
+        if (str.find("-") == 4)
+            input_facet->set_iso_extended_format();
+        else /* Not in iso format, try squashed format. */
+            input_facet->format("%Y%m%d%H%M%S");
         PTime pdt(not_a_date_time);
         ss >> pdt;
-        if (pdt.is_special())
-        {
-            input_facet->format("%Y%m%d%H%M%S");
-            ss.clear(); //Reset to the beginning.
-            ss.seekg(0);
-            ss >> pdt;
-        }
         m_time = LDT(pdt.date(), pdt.time_of_day(), tzptr,
                          LDTBase::NOT_DATE_TIME_ON_ERROR);
     }
@@ -450,7 +446,7 @@ GncDateTime::GncDateTime(const time64 time) :
     m_impl(new GncDateTimeImpl(time)) {}
 GncDateTime::GncDateTime(const struct tm tm) :
     m_impl(new GncDateTimeImpl(tm)) {}
-GncDateTime::GncDateTime(const std::string str, std::string fmt) :
+GncDateTime::GncDateTime(const std::string str) :
     m_impl(new GncDateTimeImpl(str)) {}
 GncDateTime::~GncDateTime() = default;
 

libgnucash/engine/test/gtest-gnc-datetime.cpp

@@ -293,6 +293,16 @@ TEST(gnc_datetime_constructors, test_string_constructor)
     EXPECT_EQ(tm.tm_hour, 15);
     EXPECT_EQ(tm.tm_min, 8);
     EXPECT_EQ(tm.tm_sec, 19);
+/* Squashed format from SQLite3 databases */
+    timestr = "20151205115703";
+    GncDateTime time4(timestr);
+    tm = time4.utc_tm();
+    EXPECT_EQ(tm.tm_year, 115);
+    EXPECT_EQ(tm.tm_mon, 11);
+    EXPECT_EQ(tm.tm_mday, 5);
+    EXPECT_EQ(tm.tm_hour,11);
+    EXPECT_EQ(tm.tm_min, 57);
+    EXPECT_EQ(tm.tm_sec, 3);
 }
 
 TEST(gnc_datetime_constructors, test_struct_tm_constructor)