Index: src/library/base/R/mapply.R
===================================================================
--- src/library/base/R/mapply.R	(revision 39024)
+++ src/library/base/R/mapply.R	(working copy)
@@ -3,8 +3,16 @@
     FUN <- match.fun(FUN)
     dots <- list(...)
 
+    if(!is.null(names(dots[[1]]))) {
+        isNamed <- TRUE
+        namesX <- names(dots[[1]])
+    } else {
+        isNamed <- FALSE
+    }
+
     answer<-.Call("do_mapply", FUN, dots, MoreArgs, environment(),
                   PACKAGE="base")
+    if(isNamed) names(answer) <- namesX
 
     if (USE.NAMES && length(dots) && is.character(dots[[1]]) &&
         is.null(names(answer))) names(answer) <- dots[[1]]
@@ -47,4 +55,4 @@
     }
     formals(FUNV) <- formals(FUN)
     FUNV
-}
\ No newline at end of file
+}