Merge pull request #2035 from MichaelChirico/formatITime

Closes #2032 -- error in format.ITime edge case (0-length input)

NEWS.md

@@ -34,6 +34,8 @@
 
 7. Seg fault in `rbindlist()` when one or more items are empty, [#2019](https://github.com/Rdatatable/data.table/issues/2019). Thanks Michael Lang for the pull request.
 
+2. Fixed an error in `format.ITime` that was preventing printing of 0-length `ITime` objects, [#2032](https://github.com/Rdatatable/data.table/issues/2032). Thanks @MichaelChirico.
+
 #### NOTES
 
 

R/IDateTime.R

@@ -120,9 +120,7 @@ as.character.ITime <- format.ITime <- function(x, ...) {
     hh <- x %/% 3600L
     mm <- (x - hh * 3600L) %/% 60L
     ss <- trunc(x - hh * 3600L - 60L * mm)
-    res = paste(substring(paste("0", hh, sep = ""), nchar(paste(hh))), 
-              substring(paste("0", mm, sep = ""), nchar(paste(mm))), 
-              substring(paste("0", ss, sep = ""), nchar(paste(ss))), sep = ":")
+    res = sprintf('%02d:%02d:%02d', hh, mm, ss)
     # Fix for #1354, so that "NA" input is handled correctly.
     if (is.na(any(neg))) res[is.na(x)] = NA
     neg = which(neg)

inst/tests/tests.Rraw

@@ -9907,6 +9907,9 @@ x = list(list(a = 1), list(), list(a = 2))
 ans = data.table(id=c(1L,3L),a=c(1,2))
 for (i in 1:100) test(1763, rbindlist(x, idcol="id"), ans)
 
+# as.ITime(character(0)) used to fail, #2032
+test(1764, capture.output(format(as.ITime(character(0)))), "character(0)")
+
 ##########################
 
 # TODO: Tests involving GForce functions needs to be run with optimisation level 1 and 2, so that both functions are tested all the time.