Bug 113733: nsXPIDLCString doesn't have an assignment operator.

adds |operator=( const self_type& )| to nsSharable{C}String and nsXPIDL{C}String, to prevent the compiler from synthesizing its own (which won't do the right thing).

This should fix a bunch of XPIDLString-related cfront compile warnings.

original patch by jag, updated by me; r=dbaron, sr=jag.

string/public/nsSharableString.h

@@ -72,6 +72,13 @@ class NS_COM nsSharableString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type& operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * The |Adopt| method assigns a raw, null-terminated, character
        * buffer to this string object by transferring ownership of that
@@ -134,6 +141,13 @@ class NS_COM nsSharableCString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type& operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * The |Adopt| method assigns a raw, null-terminated, character
        * buffer to this string object by transferring ownership of that

string/public/nsXPIDLString.h

@@ -170,6 +170,7 @@ class NS_COM nsXPIDLString
         }
 #endif
 
+      // |operator=| does not inherit, so we must provide it again
       self_type&
       operator=( const abstract_string_type& aReadable )
         {
@@ -177,6 +178,14 @@ class NS_COM nsXPIDLString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type&
+      operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * This is an override of a non-virtual function on
        * |nsSharableString|.  This override is not necessary, but it can
@@ -282,6 +291,7 @@ class NS_COM nsXPIDLCString
         }
 #endif
 
+      // |operator=| does not inherit, so we must provide it again
       self_type&
       operator=( const abstract_string_type& aReadable )
         {
@@ -289,6 +299,14 @@ class NS_COM nsXPIDLCString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type&
+      operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * This is an override of a non-virtual function on
        * |nsSharableCString|.  This override is not necessary, but it can

xpcom/string/public/nsSharableString.h

@@ -72,6 +72,13 @@ class NS_COM nsSharableString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type& operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * The |Adopt| method assigns a raw, null-terminated, character
        * buffer to this string object by transferring ownership of that
@@ -134,6 +141,13 @@ class NS_COM nsSharableCString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type& operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * The |Adopt| method assigns a raw, null-terminated, character
        * buffer to this string object by transferring ownership of that

xpcom/string/public/nsXPIDLString.h

@@ -170,6 +170,7 @@ class NS_COM nsXPIDLString
         }
 #endif
 
+      // |operator=| does not inherit, so we must provide it again
       self_type&
       operator=( const abstract_string_type& aReadable )
         {
@@ -177,6 +178,14 @@ class NS_COM nsXPIDLString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type&
+      operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * This is an override of a non-virtual function on
        * |nsSharableString|.  This override is not necessary, but it can
@@ -282,6 +291,7 @@ class NS_COM nsXPIDLCString
         }
 #endif
 
+      // |operator=| does not inherit, so we must provide it again
       self_type&
       operator=( const abstract_string_type& aReadable )
         {
@@ -289,6 +299,14 @@ class NS_COM nsXPIDLCString
           return *this;
         }
 
+      // copy-assignment operator.  I must define my own if I don't want the compiler to make me one
+      self_type&
+      operator=( const self_type& aReadable )
+        {
+          Assign(aReadable);
+          return *this;
+        }
+
       /**
        * This is an override of a non-virtual function on
        * |nsSharableCString|.  This override is not necessary, but it can