Previously, a race condition could occur if, while a process had called make_tex (generating the tex file in the global cache) and was going to call the latex subprocess (to generate the dvi file), another process also called make_tex for the same tex string and started rewriting the tex source. In that case, the latex subprocess could see a partially written (invalid) tex source.

Fix that by generating the tex source in a process-private temporary directory, where the latex process is already going to run anyways. (This is cheap compared to the latex subprocess invocation.)

See#30420 (comment) (point (2)).

Edit: did the same to make_png.

PR summary

PR checklist

• "closes #0000" is in the body of the PR description tolink the related issue
• new and changed code istested
• Plotting related features are demonstrated in anexample
• New Features andAPI Changes are noted with adirective and release note
• Documentation complies withgeneral anddocstring guidelines