diff --git a/mozilla/string/obsolete/nsXPIDLString.cpp b/mozilla/string/obsolete/nsXPIDLString.cpp
index 0a69f8c6eab..6b2a5bbe841 100644
--- a/mozilla/string/obsolete/nsXPIDLString.cpp
+++ b/mozilla/string/obsolete/nsXPIDLString.cpp
@@ -119,6 +119,18 @@ nsXPIDLCString::~nsXPIDLCString()
 }
 
 
+nsXPIDLCString& nsXPIDLCString::operator =(const char* aCString)
+{
+    if (mBufOwner && mBuf)
+        XPIDL_FREE(mBuf);
+	
+    mBuf = Copy(aCString);
+    mBufOwner = PR_TRUE;
+    
+    return *this;
+}
+
+
 nsXPIDLCString::operator const char*()
 {
     return mBuf;
diff --git a/mozilla/string/obsolete/nsXPIDLString.h b/mozilla/string/obsolete/nsXPIDLString.h
index 5c36d9c9f3d..696bc24519c 100644
--- a/mozilla/string/obsolete/nsXPIDLString.h
+++ b/mozilla/string/obsolete/nsXPIDLString.h
@@ -214,6 +214,11 @@ public:
 
     virtual ~nsXPIDLCString();
 
+	/**
+	 * Assign a single-byte string to this wrapper. Copies and owns the result.
+	 */
+	nsXPIDLCString& operator =(const char* aString);
+
     /**
      * Return a reference to the immutable single-byte string.
      */
diff --git a/mozilla/xpcom/ds/nsXPIDLString.cpp b/mozilla/xpcom/ds/nsXPIDLString.cpp
index 0a69f8c6eab..6b2a5bbe841 100644
--- a/mozilla/xpcom/ds/nsXPIDLString.cpp
+++ b/mozilla/xpcom/ds/nsXPIDLString.cpp
@@ -119,6 +119,18 @@ nsXPIDLCString::~nsXPIDLCString()
 }
 
 
+nsXPIDLCString& nsXPIDLCString::operator =(const char* aCString)
+{
+    if (mBufOwner && mBuf)
+        XPIDL_FREE(mBuf);
+	
+    mBuf = Copy(aCString);
+    mBufOwner = PR_TRUE;
+    
+    return *this;
+}
+
+
 nsXPIDLCString::operator const char*()
 {
     return mBuf;
diff --git a/mozilla/xpcom/ds/nsXPIDLString.h b/mozilla/xpcom/ds/nsXPIDLString.h
index 5c36d9c9f3d..696bc24519c 100644
--- a/mozilla/xpcom/ds/nsXPIDLString.h
+++ b/mozilla/xpcom/ds/nsXPIDLString.h
@@ -214,6 +214,11 @@ public:
 
     virtual ~nsXPIDLCString();
 
+	/**
+	 * Assign a single-byte string to this wrapper. Copies and owns the result.
+	 */
+	nsXPIDLCString& operator =(const char* aString);
+
     /**
      * Return a reference to the immutable single-byte string.
      */
diff --git a/mozilla/xpcom/string/obsolete/nsXPIDLString.cpp b/mozilla/xpcom/string/obsolete/nsXPIDLString.cpp
index 0a69f8c6eab..6b2a5bbe841 100644
--- a/mozilla/xpcom/string/obsolete/nsXPIDLString.cpp
+++ b/mozilla/xpcom/string/obsolete/nsXPIDLString.cpp
@@ -119,6 +119,18 @@ nsXPIDLCString::~nsXPIDLCString()
 }
 
 
+nsXPIDLCString& nsXPIDLCString::operator =(const char* aCString)
+{
+    if (mBufOwner && mBuf)
+        XPIDL_FREE(mBuf);
+	
+    mBuf = Copy(aCString);
+    mBufOwner = PR_TRUE;
+    
+    return *this;
+}
+
+
 nsXPIDLCString::operator const char*()
 {
     return mBuf;
diff --git a/mozilla/xpcom/string/obsolete/nsXPIDLString.h b/mozilla/xpcom/string/obsolete/nsXPIDLString.h
index 5c36d9c9f3d..696bc24519c 100644
--- a/mozilla/xpcom/string/obsolete/nsXPIDLString.h
+++ b/mozilla/xpcom/string/obsolete/nsXPIDLString.h
@@ -214,6 +214,11 @@ public:
 
     virtual ~nsXPIDLCString();
 
+	/**
+	 * Assign a single-byte string to this wrapper. Copies and owns the result.
+	 */
+	nsXPIDLCString& operator =(const char* aString);
+
     /**
      * Return a reference to the immutable single-byte string.
      */