From fe188957a9897fc9b4297249261fdd02294959b1 Mon Sep 17 00:00:00 2001
From: Fulvio <fbf@libero.it>
Date: Wed, 1 Feb 2023 17:49:48 +0100
Subject: [PATCH] Report invalid dates when parsing PGNs.

---
 src/date.h     | 11 ++++-------
 src/pgnparse.h | 43 ++++++++++++++++++++++++++++++++-----------
 2 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/src/date.h b/src/date.h
index cf3a608c..5bc45b4e 100644
--- a/src/date.h
+++ b/src/date.h
@@ -75,13 +75,10 @@ date_GetDay (dateT date)
     return (uint32_t) (date & 31);
 }
 
-//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-//### date_GetMonthDay():
-//      Get the month and day; used to check for year-only dates. S.A
-inline uint32_t
-date_GetMonthDay (dateT date)
-{
-    return (uint32_t) (date & 511);
+// Return true if the date does not include the year, the month or the day.
+inline bool date_isPartial(dateT date) {
+	return date_GetYear(date) == 0 || date_GetMonth(date) == 0 ||
+	       date_GetDay(date) == 0;
 }
 
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/src/pgnparse.h b/src/pgnparse.h
index d470bcad..168f8641 100644
--- a/src/pgnparse.h
+++ b/src/pgnparse.h
@@ -27,6 +27,7 @@
 #include "game.h"
 #include "pgn_lexer.h"
 #include <string>
+#include <string_view>
 #include <vector>
 
 /**
@@ -160,12 +161,28 @@ class PgnVisitor {
 		if (tagLen == 0 || tagLen + valueLen > 240 ||
 		    !parseTagPair(tag.first, tagLen, value)) // Failure
 		{
-			std::string err(tag.first, tag.second);
-			err.append(" \"");
-			err.append(value.first, value.second);
-			err.push_back('"');
-			logErr("Error parsing the tag pair: ",
-			       {err.c_str(), err.c_str() + err.size()});
+			const auto tag_sv = std::string_view(tag.first, tagLen);
+			const auto value_sv = std::string_view(value.first, valueLen);
+			std::string tag_parsed;
+			std::string value_parsed;
+			game.viewTagPairs([&](auto game_tag, auto game_value) {
+				if (tag_sv == game_tag) {
+					tag_parsed = game_tag;
+					value_parsed = game_value;
+				}
+			});
+			if (tag_sv != tag_parsed || value_sv != value_parsed) {
+				std::string err(tag_sv);
+				err.append(" \"");
+				err.append(value_sv);
+				err.append("\" ==> ");
+				err.append(tag_parsed);
+				err.append(" \"");
+				err.append(value_parsed);
+				err.push_back('"');
+				logWarning("Error parsing the tag pair: ",
+				           {err.c_str(), err.c_str() + err.size()});
+			}
 		}
 		return true;
 	}
@@ -268,8 +285,9 @@ class PgnVisitor {
 			break;
 		case 4:
 			if (std::equal(tag, tag + 4, "Date")) {
-				game.SetDate(date_parsePGNTag(value));
-				return true;
+				const auto date = date_parsePGNTag(value);
+				game.SetDate(date);
+				return !date_isPartial(date);
 			}
 			break;
 		case 6:
@@ -280,13 +298,16 @@ class PgnVisitor {
 			if (std::equal(tag, tag + 7, "UTCDate") &&
 			    game.GetDate() == ZERO_DATE) {
 				// Add two tags: "UTCDate" and the standard "Date".
-				game.SetDate(date_parsePGNTag(value));
+				const auto date = date_parsePGNTag(value);
+				if (!date_isPartial(date))
+					game.SetDate(date);
 			}
 			break;
 		case 9:
 			if (std::equal(tag, tag + 9, "EventDate")) {
-				game.SetEventDate(date_parsePGNTag(value));
-				return true;
+				const auto date = date_parsePGNTag(value);
+				game.SetEventDate(date);
+				return !date_isPartial(date);
 			}
 			if (std::equal(tag, tag + 9, "ScidFlags")) {
 				game.SetScidFlags(value.first,