YA tweak at "balanced" in [[.POSIXlt

git-svn-id: https://svn.r-project.org/R/trunk@88450 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: maechler

doc/NEWS.Rd

@@ -9,7 +9,7 @@
   \subsection{SIGNIFICANT USER-VISIBLE CHANGES}{
     \itemize{
       \item The R citation now provides a \abbr{DOI}
-      (\I{10.32614/R.manuals}): please update your 
+      (\I{10.32614/R.manuals}): please update your
       bibliographies accordingly.
     }
   }
@@ -247,6 +247,9 @@
       \item Subassigning \code{"POSIXlt"}, i.e., \code{<tdat>[i] <- val}
       and \code{<tdat>[[i]] <- val} now rebalance as they should,
       thanks to \I{Mikael Jagan}'s \PR{18919}.
+
+      \item \code{<POSIXlt>[*]} (re-)setting \code{"balanced"}, fixing
+      \PR{18681} comment #7, thanks to \I{Mikael Jagan}.
     }
   }
 }

src/library/base/R/datetime.R

@@ -1547,8 +1547,9 @@ OlsonNames <- function(tzdir = NULL)
                 domain = NA)
         i <- idx
     }
-    .POSIXlt(lapply(unCfillPOSIXlt(x), `[[`, i, drop = drop),
-             attr(x, "tzone"), oldClass(x))
+    `attr<-`(.POSIXlt(lapply(unCfillPOSIXlt(x), `[[`, i, drop = drop),
+                      attr(x, "tzone"), oldClass(x)),
+             "balanced", if(isTRUE(attr(x, "balanced"))) TRUE else NA)
 }
 
 as.list.POSIXlt <- function(x, ...)

tests/datetime3.R

@@ -775,6 +775,16 @@ if(!tz %in% OlsonNames()) {
     stopifnot(identical(x1, x), identical(x2, x))
 })
 ## x1, x2 were identical but differing from x
+n <- 4L # >= 3 for NA-filling in subassignment
+z1 <- z2 <- `attr<-`(z <- as.POSIXlt(.POSIXct(double(n), "UTC")),
+                     "balanced", NULL)
+z1$year <- z2$year <- z$year[1L] # "un"balance
+z1[n] <- z2[[n]] <- z[[1L]]      # check `[<-` and `[[<-`
+stopifnot(z2[,"year"] == 70) # was (70 NA NA 70) previously
+identicalPlt <- function(x, y, ...)
+    identical(balancePOSIXlt(x), balancePOSIXlt(y), ...)
+stopifnot(identicalPlt(z1, z), identicalPlt(z2, z))
+## failed previously, incl in rev 88441