From: Shane Carr <shane@unicode.org>
Date: Fri, 1 Dec 2017 23:03:52 +0000 (+0000)
Subject: ICU-13492 Fixing currency fraction length fallbacks in the DecimalFormat-to-NumberFor... 
X-Git-Tag: release-61-rc~175
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ceca3c430c206ac8cbb4c71c6c1560665ded57f1;p=icu

ICU-13492 Fixing currency fraction length fallbacks in the DecimalFormat-to-NumberFormatter mapping function.

X-SVN-Rev: 40684
---

diff --git a/icu4j/main/classes/core/src/com/ibm/icu/number/NumberPropertyMapper.java b/icu4j/main/classes/core/src/com/ibm/icu/number/NumberPropertyMapper.java
index 5c6a08c0103..f1cdafe1dec 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/number/NumberPropertyMapper.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/number/NumberPropertyMapper.java
@@ -122,6 +122,21 @@ final class NumberPropertyMapper {
         MathContext mathContext = RoundingUtils.getMathContextOrUnlimited(properties);
         boolean explicitMinMaxFrac = minFrac != -1 || maxFrac != -1;
         boolean explicitMinMaxSig = minSig != -1 || maxSig != -1;
+        // Resolve min/max frac for currencies, required for the validation logic and for when minFrac or maxFrac was
+        // set (but not both) on a currency instance.
+        // NOTE: Increments are handled in "Rounder.constructCurrency()".
+        if (useCurrency) {
+            if (minFrac == -1 && maxFrac == -1) {
+                minFrac = currency.getDefaultFractionDigits(currencyUsage);
+                maxFrac = currency.getDefaultFractionDigits(currencyUsage);
+            } else if (minFrac == -1) {
+                minFrac = Math.min(maxFrac, currency.getDefaultFractionDigits(currencyUsage));
+            } else if (maxFrac == -1) {
+                maxFrac = Math.max(minFrac, currency.getDefaultFractionDigits(currencyUsage));
+            } else {
+                // No-op: user override for both minFrac and maxFrac
+            }
+        }
         // Validate min/max int/frac.
         // For backwards compatibility, minimum overrides maximum if the two conflict.
         // The following logic ensures that there is always a minimum of at least one digit.
diff --git a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
index 74290f3b0b0..c7b7282acda 100644
--- a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
+++ b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/format/NumberFormatTest.java
@@ -5566,7 +5566,7 @@ public class NumberFormatTest extends TestFmwk {
         df.setMaximumFractionDigits(3);
         expect2(df, 35.0, "$35.000");
         df.setMinimumFractionDigits(-1);
-        expect2(df, 35.0, "$35");
+        expect2(df, 35.0, "$35.00");
         df.setMaximumFractionDigits(-1);
         expect2(df, 35.0, "$35.00");
     }
@@ -5916,4 +5916,21 @@ public class NumberFormatTest extends TestFmwk {
         expect2(df, 100, "a100");
         expect2(df, -100, "-a100");
     }
+
+    @Test
+    public void TestCurrencyRoundingMinWithoutMax() {
+        NumberFormat currencyFormat = DecimalFormat.getCurrencyInstance(Locale.US);
+        currencyFormat.setCurrency(Currency.getInstance("AUD"));
+        currencyFormat.setMinimumFractionDigits(0);
+        expect(currencyFormat, 0.001, "A$0");
+
+        // NOTE: The size of the increment takes precedent over minFrac since ICU 59.
+        // CAD-Cash uses nickel rounding.
+        currencyFormat = DecimalFormat.getCurrencyInstance(Locale.US);
+        currencyFormat.setCurrency(Currency.getInstance("CAD"));
+        ((DecimalFormat)currencyFormat).setCurrencyUsage(CurrencyUsage.CASH);
+        currencyFormat.setMinimumFractionDigits(0);
+        // expect(currencyFormat, 0.08, "CA$0.1");  // ICU 58 and down
+        expect(currencyFormat, 0.08, "CA$0.10");  // ICU 59 and up
+    }
 }