Reseting `tinytheme()` in sourced script yields LHS margin errors for _preceding_ plots

[grantmcdermott]

It took me a while to isolate this down to a simple MWE, since I first observed the behaviour in a more complicated example. But consider the following script:

library(tinyplot)
tinytheme("classic")
tinyplot(I(mpg * 1000) ~ wt, data = mtcars)
# Reset the theme
tinytheme()

Running this code interactively works exactly as expected. However, if I source it by copying it and running reprex::reprex(), I get the following, with overlapping y-axis text:

library(tinyplot)
tinytheme("classic")
tinyplot(I(mpg * 1000) ~ wt, data = mtcars)

# Reset the theme
tinytheme()

^{Created on 2025-09-14 with reprex v2.1.1}

The culprit appears to be that the LHS margin hasn't adjusted properly. What's truly odd here is that the problem only occurs if you reset the theme, i.e. call tinytheme() at the end. In other words, it somehow affects the preceding plot. (??) Compare the reprex::reprex() when I drop the last two lines:

library(tinyplot) 
tinytheme("classic")
tinyplot(I(mpg * 1000) ~ wt, data = mtcars)

^{Created on 2025-09-14 with reprex v2.1.1}

Now, we get the expected display.

Off the bat, I genuinely don't understand what's causing this. But I did notice that this issue is also present in our ?tinytheme online documentation (and similarly if you source the examples locally):

[grantmcdermott]

Running this code interactively works exactly as expected.

Actually, that's not quite correct. Running all the text in one go also yields the same undesirable overlapping text.
:-/