From saikat@stat.wisc.edu  Thu Jan 20 18:55:15 2000
From: saikat@stat.wisc.edu (Saikat DebRoy)
Date: 20 Jan 2000 12:55:15 -0600
Subject: bug in setting length of a list
Message-ID: <qxpk8l4shd8.fsf@ludwig.stat.wisc.edu>

Setting the length of a list object nullifies the whole list!

> foo <- list(a=1)
> foo
$a
[1] 1

> length(foo) <- 2
> foo
[[1]]
NULL

[[2]]
NULL


The fix is to patch R/src/main/builtin.c with the following.

===================================================================
--- r-devel/src/main/builtin.c  Sat Dec 11 15:11:05 1999
+++ r-devel.mod/src/main/builtin.c      Wed Jan 19 18:01:10 2000
@@ -508,6 +508,14 @@
            CAR(t) = CAR(x);
            TAG(t) = TAG(x);
        }
+    case VECSXP:
+       for (i = 0; i < len; i++)
+           if (i < lenx) {
+               VECTOR(rval)[i] = VECTOR(x)[i];
+               if (xnames != R_NilValue)
+                   STRING(names)[i] = STRING(xnames)[i];
+           }
+       break;
     }
     if (isVector(x) && xnames != R_NilValue)
        setAttrib(rval, R_NamesSymbol, names);

===================================================================
--please do not edit the information below--

Version:
 platform = i686-unknown-linux
 arch = i686
 os = linux
 system = i686, linux
 status = Under development (unstable)
 major = 0
 minor = 99.0
 year = 2000
 month = January
 day = 20
 language = R

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bug in setting length of a list
Saikat DebRoy