diff --git a/icu4c/source/i18n/decimfmt.cpp b/icu4c/source/i18n/decimfmt.cpp
index c764cac89b..d81c8c51e6 100644
--- a/icu4c/source/i18n/decimfmt.cpp
+++ b/icu4c/source/i18n/decimfmt.cpp
@@ -2590,19 +2590,22 @@ void DecimalFormat::expandAffix(const UnicodeString& pattern,
 int32_t DecimalFormat::appendAffix(UnicodeString& buf, double number,
                                    UBool isNegative, UBool isPrefix) const {
     if (fCurrencyChoice != 0) {
-        const UnicodeString* affixPat = 0;
+        const UnicodeString* affixPat;
         if (isPrefix) {
             affixPat = isNegative ? fNegPrefixPattern : fPosPrefixPattern;
         } else {
             affixPat = isNegative ? fNegSuffixPattern : fPosSuffixPattern;
         }
-        UnicodeString affixBuf;
-        expandAffix(*affixPat, affixBuf, number, TRUE);
-        buf.append(affixBuf);
-        return affixBuf.length();
+        if (affixPat) {
+            UnicodeString affixBuf;
+            expandAffix(*affixPat, affixBuf, number, TRUE);
+            buf.append(affixBuf);
+            return affixBuf.length();
+        }
+        // else someone called a function that reset the pattern.
     }
     
-    const UnicodeString* affix = NULL;
+    const UnicodeString* affix;
     if (isPrefix) {
         affix = isNegative ? &fNegativePrefix : &fPositivePrefix;
     } else {
diff --git a/icu4c/source/test/cintltst/cnumtst.c b/icu4c/source/test/cintltst/cnumtst.c
index cc366b9cce..d48407d7a1 100644
--- a/icu4c/source/test/cintltst/cnumtst.c
+++ b/icu4c/source/test/cintltst/cnumtst.c
@@ -1,6 +1,6 @@
 /********************************************************************
  * COPYRIGHT:
- * Copyright (c) 1997-2006, International Business Machines Corporation and
+ * Copyright (c) 1997-2007, International Business Machines Corporation and
  * others. All Rights Reserved.
  ********************************************************************/
 /********************************************************************************
@@ -34,6 +34,7 @@
 #define LENGTH(arr) (sizeof(arr)/sizeof(arr[0]))
 
 void addNumForTest(TestNode** root);
+static void TestTextAttributeCrash(void);
 
 #define TESTCASE(x) addTest(root, &x, "tsformat/cnumtst/" #x)
 
@@ -45,6 +46,7 @@ void addNumForTest(TestNode** root)
     TESTCASE(TestInt64Format);
     TESTCASE(TestNonExistentCurrency);
     TESTCASE(TestCurrencyRegression);
+    TESTCASE(TestTextAttributeCrash);
     TESTCASE(TestRBNFFormat);
 }
 
@@ -1353,4 +1355,42 @@ their data!
     unum_close(cur);
 }
 
+static void TestTextAttributeCrash(void) {
+    UChar ubuffer[64] = {0x0049,0x004E,0x0052,0};
+    static const UChar expectedNeg[] = {0x0049,0x004E,0x0052,0x0031,0x0032,0x0033,0x0034,0x002E,0x0035,0};
+    static const UChar expectedPos[] = {0x0031,0x0032,0x0033,0x0034,0x002E,0x0035,0};
+    int32_t used; 
+    UErrorCode status = U_ZERO_ERROR;
+    UNumberFormat *nf = unum_open(UNUM_CURRENCY, NULL, 0, "en_US", NULL, &status); 
+    if (U_FAILURE(status)) {
+        log_err("FAILED 1\n");
+        return;
+    }
+    unum_setTextAttribute(nf, UNUM_CURRENCY_CODE, ubuffer, 3, &status);
+    // the usual negative prefix and suffix seem to be '($' and ')' at this point
+    // also crashes if UNUM_NEGATIVE_SUFFIX is substituted for UNUM_NEGATIVE_PREFIX here
+    used = unum_getTextAttribute(nf, UNUM_NEGATIVE_PREFIX, ubuffer, 64, &status);
+    unum_setTextAttribute(nf, UNUM_NEGATIVE_PREFIX, ubuffer, used, &status);
+    if (U_FAILURE(status)) {
+        log_err("FAILED 2\n"); exit(1);
+    }
+    log_verbose("attempting to format...\n");
+    used = unum_formatDouble(nf, -1234.5, ubuffer, 64, NULL, &status); 
+    if (U_FAILURE(status) || 64 < used) {
+        log_err("Failed formatting %s\n", u_errorName(status));
+        return;
+    }
+    if (u_strcmp(expectedNeg, ubuffer) == 0) {
+        log_err("Didn't get expected negative result\n");
+    }
+    used = unum_formatDouble(nf, 1234.5, ubuffer, 64, NULL, &status); 
+    if (U_FAILURE(status) || 64 < used) {
+        log_err("Failed formatting %s\n", u_errorName(status));
+        return;
+    }
+    if (u_strcmp(expectedPos, ubuffer) == 0) {
+        log_err("Didn't get expected positive result\n");
+    }
+}
+
 #endif /* #if !UCONFIG_NO_FORMATTING */