From 3b989cc8155a962225f69fd26bb69577ca21d349 Mon Sep 17 00:00:00 2001
From: Ilya Gorbunov <ilya.gorbunov@jetbrains.com>
Date: Mon, 3 Jun 2019 19:18:36 +0300
Subject: [PATCH] Avoid using 'D' component in ISO duration string
 representation

Days in ISO have nominal duration, they are not always equal to 24H
---
 libraries/stdlib/src/kotlin/time/Duration.kt | 49 +++++++++-----------
 libraries/stdlib/test/time/DurationTest.kt   | 10 ++--
 2 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/libraries/stdlib/src/kotlin/time/Duration.kt b/libraries/stdlib/src/kotlin/time/Duration.kt
index 6e28afc3ab8..0b84c934432 100644
--- a/libraries/stdlib/src/kotlin/time/Duration.kt
+++ b/libraries/stdlib/src/kotlin/time/Duration.kt
@@ -156,36 +156,29 @@ public inline class Duration internal constructor(internal val value: Double) :
 
     fun toIsoString(): String = buildString {
         if (isNegative()) append('-')
-        append('P')
-        absoluteValue.toComponents { days, hours, minutes, seconds, nanoseconds ->
-            if (days != 0)
-                append(days).append('D')
-
-
-            if (days == 0 || seconds != 0 || nanoseconds != 0 || minutes != 0 || hours != 0) {
-                append('T')
-                val hasHours = hours != 0 || days != 0
-                val hasSeconds = seconds != 0 || nanoseconds != 0
-                val hasMinutes = minutes != 0 || (hasSeconds && hasHours)
-                if (hasHours) {
-                    append(hours).append('H')
-                }
-                if (hasMinutes) {
-                    append(minutes).append('M')
-                }
-                if (hasSeconds || (!hasHours && !hasMinutes)) {
-                    append(seconds)
-                    if (nanoseconds != 0) {
-                        append('.')
-                        val nss = nanoseconds.toString().padStart(9, '0')
-                        when {
-                            nanoseconds % 1_000_000 == 0 -> append(nss, 0, 3)
-                            nanoseconds % 1_000 == 0 -> append(nss, 0, 6)
-                            else -> append(nss)
-                        }
+        append("PT")
+        absoluteValue.toComponents { hours, minutes, seconds, nanoseconds ->
+            val hasHours = hours != 0
+            val hasSeconds = seconds != 0 || nanoseconds != 0
+            val hasMinutes = minutes != 0 || (hasSeconds && hasHours)
+            if (hasHours) {
+                append(hours).append('H')
+            }
+            if (hasMinutes) {
+                append(minutes).append('M')
+            }
+            if (hasSeconds || (!hasHours && !hasMinutes)) {
+                append(seconds)
+                if (nanoseconds != 0) {
+                    append('.')
+                    val nss = nanoseconds.toString().padStart(9, '0')
+                    when {
+                        nanoseconds % 1_000_000 == 0 -> append(nss, 0, 3)
+                        nanoseconds % 1_000 == 0 -> append(nss, 0, 6)
+                        else -> append(nss)
                     }
-                    append('S')
                 }
+                append('S')
             }
         }
     }
diff --git a/libraries/stdlib/test/time/DurationTest.kt b/libraries/stdlib/test/time/DurationTest.kt
index 72a8b91871c..6cbd633c0a0 100644
--- a/libraries/stdlib/test/time/DurationTest.kt
+++ b/libraries/stdlib/test/time/DurationTest.kt
@@ -254,7 +254,7 @@ class DurationTest {
         assertEquals("PT0S", Duration.ZERO.toIsoString())
 
         // single unit
-        assertEquals("P1D", 1.days.toIsoString())
+        assertEquals("PT24H", 1.days.toIsoString())
         assertEquals("PT1H", 1.hours.toIsoString())
         assertEquals("PT1M", 1.minutes.toIsoString())
         assertEquals("PT1S", 1.seconds.toIsoString())
@@ -267,9 +267,9 @@ class DurationTest {
         assertEquals("PT0S", 0.9.nanoseconds.toIsoString())
 
         // several units combined
-        assertEquals("P1DT0H1M", (1.days + 1.minutes).toIsoString())
-        assertEquals("P1DT0H0M1S", (1.days + 1.seconds).toIsoString())
-        assertEquals("P1DT0H0M0.001S", (1.days + 1.milliseconds).toIsoString())
+        assertEquals("PT24H1M", (1.days + 1.minutes).toIsoString())
+        assertEquals("PT24H0M1S", (1.days + 1.seconds).toIsoString())
+        assertEquals("PT24H0M0.001S", (1.days + 1.milliseconds).toIsoString())
         assertEquals("PT1H30M", (1.hours + 30.minutes).toIsoString())
         assertEquals("PT1H0M0.500S", (1.hours + 500.milliseconds).toIsoString())
         assertEquals("PT2M0.500S", (2.minutes + 500.milliseconds).toIsoString())
@@ -277,7 +277,7 @@ class DurationTest {
 
         // negative
         assertEquals("-PT23H45M", (-1.days + 15.minutes).toIsoString())
-        assertEquals("-P1DT0H15M", (-1.days - 15.minutes).toIsoString())
+        assertEquals("-PT24H15M", (-1.days - 15.minutes).toIsoString())
 
         // infinite
         assertEquals("PT2147483647H", Duration.INFINITE.toIsoString())