From badd5165dac3e864efeb863da3324a57ebabc6ee Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Mon, 15 Mar 2021 20:36:49 +0300
Subject: [PATCH] Fix UBSan report in rounding to years intervals

---
 base/common/DateLUTImpl.h                                | 9 ++++++++-
 .../0_stateless/01761_round_year_bounds.reference        | 0
 tests/queries/0_stateless/01761_round_year_bounds.sql    | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 tests/queries/0_stateless/01761_round_year_bounds.reference
 create mode 100644 tests/queries/0_stateless/01761_round_year_bounds.sql

diff --git a/base/common/DateLUTImpl.h b/base/common/DateLUTImpl.h
index 6e968a0cd50..fc30ee9c6a0 100644
--- a/base/common/DateLUTImpl.h
+++ b/base/common/DateLUTImpl.h
@@ -807,7 +807,14 @@ public:
             return toFirstDayNumOfYear(v);
 
         const LUTIndex i = toLUTIndex(v);
-        return toDayNum(years_lut[lut[i].year / years * years - DATE_LUT_MIN_YEAR]);
+
+        UInt16 year = lut[i].year / years * years;
+
+        /// For example, rounding down 1925 to 100 years will be 1900, but it's less than min supported year.
+        if (unlikely(year < DATE_LUT_MIN_YEAR))
+            year = DATE_LUT_MIN_YEAR;
+
+        return toDayNum(years_lut[year - DATE_LUT_MIN_YEAR]);
     }
 
     inline ExtendedDayNum toStartOfQuarterInterval(ExtendedDayNum d, UInt64 quarters) const
diff --git a/tests/queries/0_stateless/01761_round_year_bounds.reference b/tests/queries/0_stateless/01761_round_year_bounds.reference
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/queries/0_stateless/01761_round_year_bounds.sql b/tests/queries/0_stateless/01761_round_year_bounds.sql
new file mode 100644
index 00000000000..fed12c55568
--- /dev/null
+++ b/tests/queries/0_stateless/01761_round_year_bounds.sql
@@ -0,0 +1 @@
+SELECT toStartOfInterval(toDateTime(-9223372036854775808), toIntervalYear(100), 'Europe/Moscow') FORMAT Null;