diff --git a/netwerk/base/src/nsStandardURL.cpp b/netwerk/base/src/nsStandardURL.cpp
index db6d95b0baf..273fff5ad4e 100644
--- a/netwerk/base/src/nsStandardURL.cpp
+++ b/netwerk/base/src/nsStandardURL.cpp
@@ -71,13 +71,11 @@ static PRInt32
 AppendEscaped(nsACString &buf, const char *str, PRInt32 len, PRInt16 mask)
 {
     nsCAutoString escaped;
-    NS_EscapeURL(str, len, mask, escaped);
-    if (escaped.IsEmpty())
-        buf.Append(str, len);
-    else {
-        buf.Append(escaped);
+    if (NS_EscapeURLPart(str, len, mask, escaped)) {
+        str = escaped.get();
         len = escaped.Length();
     }
+    buf.Append(str, len);
     return len;
 }
 
@@ -183,11 +181,10 @@ nsStandardURL::EscapeSegment(const char *str, const URLSegment &seg, PRInt16 mas
 {
     PRInt32 len = 0;
     if (seg.mLen > 0) {
-        NS_EscapeURL(str + seg.mPos, seg.mLen, mask, result);
-        if (result.IsEmpty())
-            len = seg.mLen;
-        else
+        if (NS_EscapeURLPart(str + seg.mPos, seg.mLen, mask, result))
             len = result.Length();
+        else
+            len = seg.mLen;
     }
     return len;
 }
@@ -873,8 +870,7 @@ nsStandardURL::SetUsername(const char *username)
 
     // escape username if necessary
     nsCAutoString escaped;
-    NS_EscapeURL(username, len, esc_Username, escaped);
-    if (!escaped.IsEmpty()) {
+    if (NS_EscapeURLPart(username, len, esc_Username, escaped)) {
         username = escaped.get();
         len = escaped.Length();
     }
@@ -934,8 +930,7 @@ nsStandardURL::SetPassword(const char *password)
 
     // escape password if necessary
     nsCAutoString escaped;
-    NS_EscapeURL(password, len, esc_Password, escaped);
-    if (!escaped.IsEmpty()) {
+    if (NS_EscapeURLPart(password, len, esc_Password, escaped)) {
         password = escaped.get();
         len = escaped.Length();
     }
@@ -1423,8 +1418,7 @@ nsStandardURL::SetQuery(const char *query)
 
     // escape query if necessary
     nsCAutoString escaped;
-    NS_EscapeURL(query, queryLen, esc_Query, escaped);
-    if (!escaped.IsEmpty()) {
+    if (NS_EscapeURLPart(query, queryLen, esc_Query, escaped)) {
         query = escaped.get();
         queryLen = escaped.Length();
     }
@@ -1475,8 +1469,7 @@ nsStandardURL::SetRef(const char *ref)
 
     // escape ref if necessary
     nsCAutoString escaped;
-    NS_EscapeURL(ref, refLen, esc_Ref, escaped);
-    if (!escaped.IsEmpty()) {
+    if (NS_EscapeURLPart(ref, refLen, esc_Ref, escaped)) {
         ref = escaped.get();
         refLen = escaped.Length();
     }
diff --git a/netwerk/base/src/nsURLHelper.cpp b/netwerk/base/src/nsURLHelper.cpp
index 72eb0970b61..286fd4e14dd 100644
--- a/netwerk/base/src/nsURLHelper.cpp
+++ b/netwerk/base/src/nsURLHelper.cpp
@@ -47,16 +47,6 @@
 #include <windows.h> // ::IsDBCSLeadByte need
 #endif
 
-/* helper call function */
-nsresult
-nsAppendURLEscapedString(nsCString& originalStr, const char* str, PRInt16 mask)
-{
-    nsCAutoString result;
-    nsresult rv = nsStdEscape(str, mask, result);
-    originalStr += result;
-    return rv;
-}
-
 /* extracts first number from a string and assumes that this is the port number*/
 PRInt32 
 ExtractPortFrom(const char* src)
diff --git a/netwerk/base/src/nsURLHelper.h b/netwerk/base/src/nsURLHelper.h
index f4b3f0ef342..9469811c596 100644
--- a/netwerk/base/src/nsURLHelper.h
+++ b/netwerk/base/src/nsURLHelper.h
@@ -47,9 +47,6 @@
 extern "C" {
 #endif
 
-/* helper call function */
-nsresult nsAppendURLEscapedString(nsCString& originalStr, const char* str, PRInt16 mask);
-
 /* Get port from string */ 
 PRInt32 ExtractPortFrom(const char* src);
 
diff --git a/xpcom/io/nsEscape.cpp b/xpcom/io/nsEscape.cpp
index ef847ce324e..f2031185906 100644
--- a/xpcom/io/nsEscape.cpp
+++ b/xpcom/io/nsEscape.cpp
@@ -349,8 +349,8 @@ const int EscapeChars[256] =
 
 NS_COM nsresult nsStdEscape(const char* str, PRInt16 mask, nsCString &result)
 {
-    result.Truncate(0);
-    nsresult rv = NS_EscapeURL(str, -1, mask, result);
+    result.Truncate();
+    nsresult rv = NS_EscapeURLPart(str, -1, mask, result);
     if (NS_SUCCEEDED(rv) && result.IsEmpty())
         result = str;
     return rv;
@@ -365,30 +365,30 @@ NS_COM nsresult nsStdUnescape(char *str, char **result)
     return NS_OK;
 }
 
-NS_COM nsresult NS_EscapeURL(const char *str,
-                             PRInt32 len,
-                             PRInt16 mask,
-                             nsACString &result)
+NS_COM PRBool NS_EscapeURLPart(const char *part,
+                               PRInt32 partLen,
+                               PRInt16 mask,
+                               nsACString &result)
 {
-    if (!str)
-        return NS_OK;
+    if (!part)
+        return PR_FALSE;
 
     int i = 0;
     static const char hexChars[] = "0123456789ABCDEF";
-    if (len < 0)
-        len = strlen(str);
+    if (partLen < 0)
+        partLen = strlen(part);
     PRBool forced = PR_FALSE;
     PRBool writing = PR_FALSE;
 
     if (mask & esc_Forced)
         forced = PR_TRUE;
 
-    register const unsigned char* src = (const unsigned char *) str;
+    register const unsigned char* src = (const unsigned char *) part;
 
     char tempBuffer[100];
     unsigned int tempBufferPos = 0;
 
-    for (i = 0; i < len; i++)
+    for (i = 0; i < partLen; i++)
     {
       unsigned char c = *src++;
 
@@ -407,8 +407,7 @@ NS_COM nsresult NS_EscapeURL(const char *str,
       {
         if (!writing)
         {
-          result.Truncate(0);
-          result.Append(str, i);
+          result.Append(part, i);
           writing = PR_TRUE;
         }
         tempBuffer[tempBufferPos++] = HEX_ESCAPE;
@@ -428,6 +427,10 @@ NS_COM nsresult NS_EscapeURL(const char *str,
       tempBuffer[tempBufferPos] = '\0';
       result += tempBuffer;
     }
-    return NS_OK;
+    return writing;
 }
 
+NS_COM void NS_UnescapeURL(char *str)
+{
+    nsUnescape(str);
+}
diff --git a/xpcom/io/nsEscape.h b/xpcom/io/nsEscape.h
index fa680a08f68..cf71f51c499 100644
--- a/xpcom/io/nsEscape.h
+++ b/xpcom/io/nsEscape.h
@@ -85,10 +85,20 @@ nsEscapeHTML2(const PRUnichar *aSourceBuffer,
   */
 
 
-  /**
-     * Constants for the mask in the call to nsStdEscape
-     */
+/**
+ * DEPRACATED API: use NS_EscapeURLPart/NS_UnescapeURL instead
+ */
+NS_COM nsresult nsStdEscape(const char* str, PRInt16 mask, nsCString &result);
+NS_COM nsresult nsStdUnescape(char* str, char **result);
 
+#ifdef __cplusplus
+}
+#endif
+
+
+/**
+ * Constants for partType in the call to NS_EscapeURLPart
+ */
 enum EscapeMask {
   esc_Scheme        = 1,
   esc_Username      = 2,
@@ -103,30 +113,28 @@ enum EscapeMask {
   esc_Forced        = 1024
 };
 
-NS_COM nsresult nsStdEscape(const char* str, PRInt16 mask, nsCString &result);
-NS_COM nsresult nsStdUnescape(char* str, char **result);
+/**
+ * NS_EscapeURLPart
+ *
+ * Escapes invalid char's in an URL segment.  Has no side-effect if the URL
+ * segment is already escaped.  Otherwise, the escaped URL segment is appended
+ * to |result|.
+ *
+ * @param part     - url segment string
+ * @param partLen  - url segment string length (-1 if unknown)
+ * @param partType - url segment type flag
+ * @param result   - result buffer, untouched if part is already escaped
+ *
+ * @return TRUE if escaping was performed, FALSE otherwise.
+ */
+NS_COM PRBool NS_EscapeURLPart(const char *part,
+                               PRInt32 partLen,
+                               PRInt16 partType,
+                               nsACString &result);
 
 /**
- * NS_EscapeURL
- *
- * Escapes invalid char's in an URL segment.
- *
- * @param str       - the url string
- * @param len       - optional string length (-1 if unknown)
- * @param mask      - url segment type mask
- * @param result    - result buffer, untouched if escaping & filtering not necessary
+ * Expands URL escape sequences.  Equivalent to nsUnescape.
  */
-NS_COM nsresult NS_EscapeURL(const char *str,
-                             PRInt32 len,
-                             PRInt16 mask,
-                             nsACString &result);
-
-#define NS_UnescapeURL(str) nsUnescape(str)
-
-#ifdef __cplusplus
-}
-#endif
-
-
+NS_COM void NS_UnescapeURL(char *str);
 
 #endif //  _ESCAPE_H_