Overflow when calling Calendar.date(from:) (#690)

Validate the given `DateComponents` values up front to align with the supported Calendar calculation date range, defined as `Date.validCalendarRange`.

We could alternatively guard all arithmetic operations with `...reportingOverflow`, but there are too many operations, and so it seems untenable. I opted for a more realistic approach instead. `_CalendarICU` unconditionally truncates values to `Int32`, so the results for `Calendar.date(from:)` have always been incorrect for distant dates anyways.

Fixed 129782208

Author: itingliu

Sources/FoundationEssentials/Calendar/Calendar_Gregorian.swift

@@ -1586,11 +1586,48 @@ internal final class _CalendarGregorian: _CalendarProtocol, @unchecked Sendable
 
     // MARK:
 
+    static func isComponentsInSupportedRange(_ components: DateComponents) -> Bool {
+        // `Date.validCalendarRange` supports approximately from year -4713 to year 506713. These valid ranges were chosen as if representing the entire supported date range in one calendar unit.
+        let validEra = -10...10
+        let validYear = -4714...506714
+        let validQuarter = -4714*4...506714*4
+        let validWeek = -4714*52...506714*52
+        let validWeekday = -4714*52*7...506714*52*7
+        let validMonth = -4714*12...506714*12
+        let validDayOfYear = -4714*365...506714*365
+        let validDayOfMonth = -4714*12*31...506714*12*31
+        let validHour = -4714*8760...Int(Int32.max)
+        let validMinute = Int(Int32.min)...Int(Int32.max)
+        let validSecond = Int(Int32.min)...Int(Int32.max)
+
+        if let value = components.era { guard validEra.contains(value) else { return false } }
+        if let value = components.year { guard validYear.contains(value) else { return false } }
+        if let value = components.quarter { guard validQuarter.contains(value) else { return false } }
+        if let value = components.weekOfYear { guard validWeek.contains(value) else { return false } }
+        if let value = components.weekOfMonth { guard validWeek.contains(value) else { return false } }
+        if let value = components.yearForWeekOfYear { guard validYear.contains(value) else { return false } }
+        if let value = components.weekday { guard validWeekday.contains(value) else { return false } }
+        if let value = components.weekdayOrdinal { guard validWeek.contains(value) else { return false } }
+        if let value = components.month { guard validMonth.contains(value) else { return false } }
+        if let value = components.dayOfYear { guard validDayOfYear.contains(value) else { return false } }
+        if let value = components.day { guard validDayOfMonth.contains(value) else { return false } }
+        if let value = components.hour { guard validHour.contains(value) else { return false } }
+        if let value = components.minute { guard validMinute.contains(value) else { return false } }
+        if let value = components.second { guard validSecond.contains(value) else { return false } }
+        return true
+    }
+
     func date(from components: DateComponents) -> Date? {
+        guard _CalendarGregorian.isComponentsInSupportedRange(components) else {
+
+            // One or more values exceeds supported date range
+            return nil
+        }
+
         // If the components specifies a new time zone, perform this calculation using the specified timezone
         // If the date falls into the skipped time frame when transitioning into DST (e.g. 1:00 - 3:00 AM for PDT), we want to treat it as if DST hasn't happened yet. So, use .former for dstRepeatedTimePolicy.
         // If the date falls into the repeated time frame when DST ends (e.g. 1:00 - 2:00 AM for PDT), we want the first instance, i.e. the instance before turning back the clock. So, use .former for dstSkippedTimePolicy.
-        date(from: components, inTimeZone: components.timeZone ?? timeZone, dstRepeatedTimePolicy: .former, dstSkippedTimePolicy: .former)
+        return date(from: components, inTimeZone: components.timeZone ?? timeZone, dstRepeatedTimePolicy: .former, dstSkippedTimePolicy: .former)
     }
 
     //  Returns the weekday with reference to `firstWeekday`, in the range of 0...6

Sources/FoundationEssentials/Date.swift

@@ -383,7 +383,7 @@ extension Date : _CustomPlaygroundQuickLookable {
 #endif // FOUNDATION_FRAMEWORK
 
 extension Date {
-    // Julian day 0 (-4713-01-01 12:00:00 +0000) in CFAbsoluteTime to 50000-01-01 00:00:00 +0000, smaller than the max time ICU supported.
+    // Julian day 0 (-4713-01-01 12:00:00 +0000) in CFAbsoluteTime to 506713-02-07 00:00:00 +0000, smaller than the max time ICU supported.
     package static let validCalendarRange = Date(timeIntervalSinceReferenceDate: TimeInterval(-211845067200.0))...Date(timeIntervalSinceReferenceDate: TimeInterval(15927175497600.0))
 
     // aka __CFCalendarValidateAndCapTimeRange

Tests/FoundationInternationalizationTests/CalendarTests.swift

@@ -1122,6 +1122,37 @@ final class CalendarTests : XCTestCase {
         // 2024-03-03T02:34:36-0800, 2024-03-11T02:34:36-0700
         try test(Date(timeIntervalSinceReferenceDate: 731154876), Date(timeIntervalSinceReferenceDate: 731842476))
     }
+
+#if !os(watchOS) // This test assumes Int is Int64
+    func test_dateFromComponentsOverflow() {
+        let calendar = Calendar(identifier: .gregorian)
+
+        do {
+            let components = DateComponents(year: -1157442765409226769, month: -1157442765409226769, day: -1157442765409226769)
+            let date = calendar.date(from: components)
+            XCTAssertNil(date)
+        }
+
+        do {
+            let components = DateComponents(year: -8935141660703064064, month: -8897841259083430780, day: -8897841259083430780)
+            let date = calendar.date(from: components)
+            XCTAssertNil(date)
+        }
+
+        do {
+            let components = DateComponents(era: 3475652213542486016, year: -1, month: 72056757140062316, day: 7812738666521952255)
+            let date = calendar.date(from: components)
+            XCTAssertNil(date)
+        }
+
+        do {
+            let components = DateComponents(weekOfYear: -5280832742222096118, yearForWeekOfYear: 182)
+            let date = calendar.date(from: components)
+            XCTAssertNil(date)
+        }
+
+    }
+#endif
 }
 
 // MARK: - Bridging Tests