diff --git a/mozilla/base/src/nsString.cpp b/mozilla/base/src/nsString.cpp
index 559280b9c0c..e7027e6c183 100644
--- a/mozilla/base/src/nsString.cpp
+++ b/mozilla/base/src/nsString.cpp
@@ -1084,6 +1084,18 @@ PRBool nsString::IsSpace(PRUnichar ch) {
   return PR_FALSE;
 }
 
+/**-------------------------------------------------------
+ *  
+ *  
+ *  @update  gess 3/31/98
+ *  @param   
+ *  @return  isalpha
+ *------------------------------------------------------*/
+PRBool nsString::IsDigit(PRUnichar ch) {
+  // XXX i18n
+  return PRBool((ch >= '0') && (ch <= '9'));
+}
+
 /**-------------------------------------------------------
  *  This method trims characters found in aTrimSet from
  *  either end of the underlying string.
diff --git a/mozilla/base/src/nsString.h b/mozilla/base/src/nsString.h
index 03501ed6fa9..7b924473907 100644
--- a/mozilla/base/src/nsString.h
+++ b/mozilla/base/src/nsString.h
@@ -133,7 +133,9 @@ class NS_BASE nsString {
                                               PRBool aEliminateTrailing=PR_TRUE);
     static  PRBool        IsSpace(PRUnichar ch);
     static  PRBool        IsAlpha(PRUnichar ch);
-  //@}
+    static  PRBool        IsDigit(PRUnichar ch);
+
+    //@}
 
   ///searching methods...
   //@{
diff --git a/mozilla/string/obsolete/nsString.cpp b/mozilla/string/obsolete/nsString.cpp
index 559280b9c0c..e7027e6c183 100644
--- a/mozilla/string/obsolete/nsString.cpp
+++ b/mozilla/string/obsolete/nsString.cpp
@@ -1084,6 +1084,18 @@ PRBool nsString::IsSpace(PRUnichar ch) {
   return PR_FALSE;
 }
 
+/**-------------------------------------------------------
+ *  
+ *  
+ *  @update  gess 3/31/98
+ *  @param   
+ *  @return  isalpha
+ *------------------------------------------------------*/
+PRBool nsString::IsDigit(PRUnichar ch) {
+  // XXX i18n
+  return PRBool((ch >= '0') && (ch <= '9'));
+}
+
 /**-------------------------------------------------------
  *  This method trims characters found in aTrimSet from
  *  either end of the underlying string.
diff --git a/mozilla/string/obsolete/nsString.h b/mozilla/string/obsolete/nsString.h
index 03501ed6fa9..7b924473907 100644
--- a/mozilla/string/obsolete/nsString.h
+++ b/mozilla/string/obsolete/nsString.h
@@ -133,7 +133,9 @@ class NS_BASE nsString {
                                               PRBool aEliminateTrailing=PR_TRUE);
     static  PRBool        IsSpace(PRUnichar ch);
     static  PRBool        IsAlpha(PRUnichar ch);
-  //@}
+    static  PRBool        IsDigit(PRUnichar ch);
+
+    //@}
 
   ///searching methods...
   //@{
diff --git a/mozilla/xpcom/ds/nsString.cpp b/mozilla/xpcom/ds/nsString.cpp
index 559280b9c0c..e7027e6c183 100644
--- a/mozilla/xpcom/ds/nsString.cpp
+++ b/mozilla/xpcom/ds/nsString.cpp
@@ -1084,6 +1084,18 @@ PRBool nsString::IsSpace(PRUnichar ch) {
   return PR_FALSE;
 }
 
+/**-------------------------------------------------------
+ *  
+ *  
+ *  @update  gess 3/31/98
+ *  @param   
+ *  @return  isalpha
+ *------------------------------------------------------*/
+PRBool nsString::IsDigit(PRUnichar ch) {
+  // XXX i18n
+  return PRBool((ch >= '0') && (ch <= '9'));
+}
+
 /**-------------------------------------------------------
  *  This method trims characters found in aTrimSet from
  *  either end of the underlying string.
diff --git a/mozilla/xpcom/ds/nsString.h b/mozilla/xpcom/ds/nsString.h
index 03501ed6fa9..7b924473907 100644
--- a/mozilla/xpcom/ds/nsString.h
+++ b/mozilla/xpcom/ds/nsString.h
@@ -133,7 +133,9 @@ class NS_BASE nsString {
                                               PRBool aEliminateTrailing=PR_TRUE);
     static  PRBool        IsSpace(PRUnichar ch);
     static  PRBool        IsAlpha(PRUnichar ch);
-  //@}
+    static  PRBool        IsDigit(PRUnichar ch);
+
+    //@}
 
   ///searching methods...
   //@{
diff --git a/mozilla/xpcom/string/obsolete/nsString.cpp b/mozilla/xpcom/string/obsolete/nsString.cpp
index 559280b9c0c..e7027e6c183 100644
--- a/mozilla/xpcom/string/obsolete/nsString.cpp
+++ b/mozilla/xpcom/string/obsolete/nsString.cpp
@@ -1084,6 +1084,18 @@ PRBool nsString::IsSpace(PRUnichar ch) {
   return PR_FALSE;
 }
 
+/**-------------------------------------------------------
+ *  
+ *  
+ *  @update  gess 3/31/98
+ *  @param   
+ *  @return  isalpha
+ *------------------------------------------------------*/
+PRBool nsString::IsDigit(PRUnichar ch) {
+  // XXX i18n
+  return PRBool((ch >= '0') && (ch <= '9'));
+}
+
 /**-------------------------------------------------------
  *  This method trims characters found in aTrimSet from
  *  either end of the underlying string.
diff --git a/mozilla/xpcom/string/obsolete/nsString.h b/mozilla/xpcom/string/obsolete/nsString.h
index 03501ed6fa9..7b924473907 100644
--- a/mozilla/xpcom/string/obsolete/nsString.h
+++ b/mozilla/xpcom/string/obsolete/nsString.h
@@ -133,7 +133,9 @@ class NS_BASE nsString {
                                               PRBool aEliminateTrailing=PR_TRUE);
     static  PRBool        IsSpace(PRUnichar ch);
     static  PRBool        IsAlpha(PRUnichar ch);
-  //@}
+    static  PRBool        IsDigit(PRUnichar ch);
+
+    //@}
 
   ///searching methods...
   //@{