The R Project SVN – R – Diff – /trunk/src/main/subscript.c

 static SEXP negativeSubscript(SEXP s, int ns, int nx)
+{
     SEXP indx;
     int stretch = 0;
-    int i;
+    int i, ix;
     PROTECT(indx = allocVector(INTSXP, nx));
     for (i = 0; i < nx; i++)
 	INTEGER(indx)[i] = 1;
-    for (i = 0; i < ns; i++)
+    for (i = 0; i < ns; i++) {
-	if (INTEGER(s)[i] != 0)
+	ix = INTEGER(s)[i];
+	if (ix != 0 && ix != NA_INTEGER && -ix <= nx)
-	    INTEGER(indx)[-INTEGER(s)[i] - 1] = 0;
+	    INTEGER(indx)[-ix - 1] = 0;
+    }
     s = logicalSubscript(indx, nx, nx, &stretch);
     UNPROTECT(1);
     return s;
+}

The R Project SVN R