Regression in linetype scales

[teunbrand]

This is a report on a regression found in revdep checks, that presents as follows:

ggplot2/revdep/problems.md

Lines 374 to 375 in d31c051

	Error in grid.Call.graphics(C_lines, x$x, x$y, index, x$arrow) :
	invalid line type: must be length 2, 4, 6 or 8

Briefly, setting a numeric linetype palette will throw error because na.value = "blank" which will cast the linetype as characters, which grid will not accept. I propose setting na.value = NA.

devtools::load_all("~/packages/ggplot2/")
#> ℹ Loading ggplot2

p <- ggplot(economics_long, aes(date, value01)) +
  geom_line(aes(linetype = variable))

p + scale_linetype_manual(values = 1:5)
#> Error in grid.Call.graphics(C_lines, x$x, x$y, index, x$arrow): invalid line type: must be length 2, 4, 6 or 8

p + scale_linetype_manual(values = 1:5, na.value = NA)

^{Created on 2024-09-11 with reprex v2.1.1}