From 6fe67b354d3f1138972b2caadc3b71a3dd14de4d Mon Sep 17 00:00:00 2001
From: djcb <djcb@djcbsoftware.nl>
Date: Sat, 17 Feb 2018 17:44:21 +0200
Subject: [PATCH] lib/parser: fix month days

In the olden days, we stored dates like e.g. 20180131121234, and do a
lexicographical check. With that, we could use e.g. upper-limits
201802312359 for "all dates in Feb 2018", even if Feb doesn't have 31
days.

However, nowadays we use time_t values, and g_date_time_new_local raises
errors for non-existent days; easiest fix is to massage things a bit; so
let's do that.

Fixes issue #1197.
---
 lib/parser/test-utils.cc |  3 +++
 lib/parser/utils.cc      | 41 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/lib/parser/test-utils.cc b/lib/parser/test-utils.cc
index 366eb33f..2c008595 100644
--- a/lib/parser/test-utils.cc
+++ b/lib/parser/test-utils.cc
@@ -62,6 +62,9 @@ test_date_basic ()
 		{ "1972-12-14T09:10:23", true,	"0093165023" },
 		{ "1854-11-18T17:10:23", true,	"0000000000" },
 
+		{ "2000-02-31T09:10:23", true,  "0951861599" },
+		{ "2000-02-29T23:59:59", true,  "0951861599" },
+
 		{ "2016",		true,	"1451599200" },
 		{ "2016",		false,  "1483221599" },
 
diff --git a/lib/parser/utils.cc b/lib/parser/utils.cc
index b33e2e3a..b8702a61 100644
--- a/lib/parser/utils.cc
+++ b/lib/parser/utils.cc
@@ -291,8 +291,40 @@ special_date (const std::string& d, bool is_first)
 		return date_boundary (is_first);
 }
 
-constexpr const char UserDateMin[] = "19700101000000";
-constexpr const char UserDateMax[] = "29991231235959";
+// if a date has a month day greater than the number of days in that month,
+// change it to a valid date point to the last second in that month
+static void
+fixup_month (struct tm *tbuf)
+{
+	decltype(tbuf->tm_mday)	max_days;
+	const auto	month = tbuf->tm_mon + 1;
+	const auto	year  = tbuf->tm_year + 1900;
+
+	switch (month) {
+	case 2:
+		if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))
+			max_days = 29;
+		else
+			max_days = 28;
+		break;
+	case 4:
+	case 6:
+	case 9:
+	case 11:
+		max_days = 30;
+		break;
+	default:
+		max_days = 31;
+		break;
+	}
+
+	if (tbuf->tm_mday > max_days) {
+		tbuf->tm_mday = max_days;
+		tbuf->tm_hour  = 23;
+		tbuf->tm_min   = 59;
+		tbuf->tm_sec   = 59;
+	}
+}
 
 std::string
 Mux::date_to_time_t_string (const std::string& dstr, bool is_first)
@@ -310,6 +342,9 @@ Mux::date_to_time_t_string (const std::string& dstr, bool is_first)
 	else if (dstr.find_first_of("ymdwhMs") != std::string::npos)
 		return delta_ymwdhMs (dstr);
 
+	constexpr char UserDateMin[] = "19700101000000";
+	constexpr char UserDateMax[] = "29991231235959";
+
 	std::string date (is_first ? UserDateMin : UserDateMax);
 	std::copy_if (dstr.begin(), dstr.end(), date.begin(),[](auto c){return isdigit(c);});
 
@@ -321,6 +356,8 @@ Mux::date_to_time_t_string (const std::string& dstr, bool is_first)
 	    !strptime (date.c_str(), "%Y", &tbuf))
 		return date_boundary (is_first);
 
+	fixup_month(&tbuf);
+
 	dtime = g_date_time_new_local (tbuf.tm_year + 1900,
 				       tbuf.tm_mon + 1,
 				       tbuf.tm_mday,