ICU-20912 Make C/J Currency consistent on lowercase/uppercase currency equality

- Adds additional tests for Currency equality behavior

icu4c/source/common/cstring.h

@@ -52,6 +52,8 @@
 U_CAPI UBool U_EXPORT2
 uprv_isASCIILetter(char c);
 
+// NOTE: For u_asciiToUpper that takes a UChar, see ustr_imp.h
+
 U_CAPI char U_EXPORT2
 uprv_toupper(char c);
 

icu4c/source/common/ustr_imp.h

@@ -46,6 +46,18 @@ ustr_hashCharsN(const char *str, int32_t length);
 U_CAPI int32_t U_EXPORT2
 ustr_hashICharsN(const char *str, int32_t length);
 
+/**
+ * Convert an ASCII-range lowercase character to uppercase.
+ * 
+ * @param c A UChar.
+ * @return If UChar is a lowercase ASCII character, returns the uppercase version.
+ *         Otherwise, returns the input character.
+ */
+U_CAPI UChar U_EXPORT2
+u_asciiToUpper(UChar c);
+
+// TODO: Add u_asciiToLower if/when there is a need for it.
+
 /**
  * NUL-terminate a UChar * string if possible.
  * If length  < destCapacity then NUL-terminate.

icu4c/source/common/ustring.cpp

@@ -1451,6 +1451,14 @@ u_unescape(const char *src, UChar *dest, int32_t destCapacity) {
     } \
 } UPRV_BLOCK_MACRO_END
 
+U_CAPI UChar U_EXPORT2
+u_asciiToUpper(UChar c) {
+    if (u'a' <= c && c <= u'z') {
+        c = c + u'A' - u'a';
+    }
+    return c;
+}
+
 U_CAPI int32_t U_EXPORT2
 u_terminateUChars(UChar *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode) {
     __TERMINATE_STRING(dest, destCapacity, length, pErrorCode);

icu4c/source/i18n/currunit.cpp

@@ -16,9 +16,11 @@
 
 #include "unicode/currunit.h"
 #include "unicode/ustring.h"
+#include "unicode/uchar.h"
 #include "cstring.h"
 #include "uinvchar.h"
 #include "charstr.h"
+#include "ustr_imp.h"
 #include "measunit_impl.h"
 
 U_NAMESPACE_BEGIN
@@ -29,22 +31,25 @@ CurrencyUnit::CurrencyUnit(ConstChar16Ptr _isoCode, UErrorCode& ec) {
     // non-NUL-terminated string to be passed as an argument, so it is not possible to check length.
     // However, we allow a NUL-terminated empty string, which should have the same behavior as nullptr.
     // Consider NUL-terminated strings of length 1 or 2 as invalid.
-    const char16_t* isoCodeToUse;
+    bool useDefault = false;
     if (U_FAILURE(ec) || _isoCode == nullptr || _isoCode[0] == 0) {
-        isoCodeToUse = kDefaultCurrency;
+        useDefault = true;
     } else if (_isoCode[1] == 0 || _isoCode[2] == 0) {
-        isoCodeToUse = kDefaultCurrency;
+        useDefault = true;
         ec = U_ILLEGAL_ARGUMENT_ERROR;
     } else if (!uprv_isInvariantUString(_isoCode, 3)) {
         // TODO: Perform a more strict ASCII check like in ICU4J isAlpha3Code?
-        isoCodeToUse = kDefaultCurrency;
+        useDefault = true;
         ec = U_INVARIANT_CONVERSION_ERROR;
     } else {
-        isoCodeToUse = _isoCode;
+        for (int32_t i=0; i<3; i++) {
+            isoCode[i] = u_asciiToUpper(_isoCode[i]);
+        }
+        isoCode[3] = 0;
+    }
+    if (useDefault) {
+        uprv_memcpy(isoCode, kDefaultCurrency, sizeof(UChar) * 4);
     }
-    // TODO: Perform uppercasing here like in ICU4J Currency.getInstance()?
-    uprv_memcpy(isoCode, isoCodeToUse, sizeof(UChar) * 3);
-    isoCode[3] = 0;
     char simpleIsoCode[4];
     u_UCharsToChars(isoCode, simpleIsoCode, 4);
     initCurrency(simpleIsoCode);
@@ -64,13 +69,13 @@ CurrencyUnit::CurrencyUnit(StringPiece _isoCode, UErrorCode& ec) {
         ec = U_INVARIANT_CONVERSION_ERROR;
     } else {
         // Have to use isoCodeBuffer to ensure the string is NUL-terminated
-        uprv_strncpy(isoCodeBuffer, _isoCode.data(), 3);
+        for (int32_t i=0; i<3; i++) {
+            isoCodeBuffer[i] = uprv_toupper(_isoCode.data()[i]);
+        }
         isoCodeBuffer[3] = 0;
         isoCodeToUse = isoCodeBuffer;
     }
-    // TODO: Perform uppercasing here like in ICU4J Currency.getInstance()?
-    u_charsToUChars(isoCodeToUse, isoCode, 3);
-    isoCode[3] = 0;
+    u_charsToUChars(isoCodeToUse, isoCode, 4);
     initCurrency(isoCodeToUse);
 }
 

icu4c/source/test/intltest/numfmtst.cpp

@@ -2172,6 +2172,10 @@ void NumberFormatTest::TestCurrencyUnit(void){
     static const char INV8[]  =  "{$%";
     static const UChar ZZZ[]  = u"zz";
     static const char ZZZ8[]  = "zz";
+    static const UChar JPY[]  = u"JPY";
+    static const char JPY8[]  =  "JPY";
+    static const UChar jpy[]  = u"jpy";
+    static const char jpy8[]  =  "jpy";
 
     UChar* EUR = (UChar*) malloc(6);
     EUR[0] = u'E';
@@ -2289,6 +2293,27 @@ void NumberFormatTest::TestCurrencyUnit(void){
     assertEquals("Copying from meter should fail", ec, U_ILLEGAL_ARGUMENT_ERROR);
     assertEquals("Copying should not give uninitialized ISO code", u"", failure.getISOCurrency());
 
+    // Test equality
+    ec = U_ZERO_ERROR;
+    assertFalse("FAIL: USD == JPY", CurrencyUnit(USD, ec) == CurrencyUnit(JPY, ec));
+    assertTrue("FAIL: USD != USD",  CurrencyUnit(USD, ec) == CurrencyUnit(USD, ec));
+    assertTrue("FAIL: JPY != jpy",  CurrencyUnit(JPY, ec) == CurrencyUnit(jpy, ec));
+    assertTrue("FAIL: jpy != JPY",  CurrencyUnit(jpy, ec) == CurrencyUnit(JPY, ec));
+
+    // Test equality with system charset instances
+    assertFalse("FAIL: USD8 == JPY8", CurrencyUnit(USD8, ec) == CurrencyUnit(JPY8, ec));
+    assertTrue("FAIL: USD8 != USD8",  CurrencyUnit(USD8, ec) == CurrencyUnit(USD8, ec));
+    assertTrue("FAIL: JPY8 != jpy8",  CurrencyUnit(JPY8, ec) == CurrencyUnit(jpy8, ec));
+    assertTrue("FAIL: jpy8 != JPY8",  CurrencyUnit(jpy8, ec) == CurrencyUnit(JPY8, ec));
+
+    // Test equality between UTF-16 and system charset instances
+    assertTrue("FAIL: USD != USD8",  CurrencyUnit(USD, ec) == CurrencyUnit(USD8, ec));
+    assertTrue("FAIL: USD8 != USD",  CurrencyUnit(USD8, ec) == CurrencyUnit(USD, ec));
+    assertTrue("FAIL: JPY != jpy8",  CurrencyUnit(JPY, ec) == CurrencyUnit(jpy8, ec));
+    assertTrue("FAIL: JPY8 != jpy",  CurrencyUnit(JPY8, ec) == CurrencyUnit(jpy, ec));
+    assertTrue("FAIL: jpy != JPY8",  CurrencyUnit(jpy, ec) == CurrencyUnit(JPY8, ec));
+    assertTrue("FAIL: jpy8 != JPY",  CurrencyUnit(jpy8, ec) == CurrencyUnit(JPY, ec));
+
     free(EUR);
     free(EUR8);
 }

icu4j/main/tests/core/src/com/ibm/icu/dev/test/util/CurrencyTest.java

@@ -52,6 +52,7 @@ public class CurrencyTest extends TestFmwk {
         Currency usd = Currency.getInstance("USD");
         /*int hash = */usd.hashCode();
         Currency jpy = Currency.getInstance("JPY");
+        Currency jpy2 = Currency.getInstance("jpy");
         if (usd.equals(jpy)) {
             errln("FAIL: USD == JPY");
         }
@@ -64,6 +65,12 @@ public class CurrencyTest extends TestFmwk {
         if (!usd.equals(usd)) {
             errln("FAIL: USD != USD");
         }
+        if (!jpy.equals(jpy2)) {
+            errln("FAIL: JPY != jpy");
+        }
+        if (!jpy2.equals(jpy)) {
+            errln("FAIL: jpy != JPY");
+        }
 
         try {
             Currency nullCurrency = Currency.getInstance((String)null);