[BUG] Incorrect display of negative signs in tick labels with non-default fonts in PDF outputs

[singularitti]

Details

When using any non-default fonts available in the GR framework with the plot function, the negative signs (-) in the tick labels on both the x and y axes are incorrectly displayed as question marks (?). This issue occurs specifically when saving plots as PDF files. Saving the same plots as PNG files shows the negative signs correctly, indicating that the issue is isolated to PDF outputs.

Steps to Reproduce

1. Install and load the Plots package.
2. Set gr() as the backend.
3. Execute the following plotting commands using various non-default fonts:

   using Plots
   gr()
   plot(-4:4, -5:3; fontfamily="Palatino Roman")  # Change font as needed
   xlabel!("-x")
   ylabel!("-y")
   savefig("x.pdf")  # Save as PDF and observe the issue
   savefig("x.png")  # Save as PNG for comparison

4. Open both x.pdf and x.png to view the results.

Expected Result

The tick labels with negative numbers should correctly display the negative sign in both PDF and PNG outputs.

Actual Result

In PDF outputs, the negative signs in the tick labels are replaced with question marks (?). In PNG outputs, the negative signs are displayed correctly.

Backends

This bug occurs on ( insert x below )

Backend	yes	no	untested
gr (default)	x
pythonplot
plotlyjs
pgfplotsx
unicodeplots
inspectdr
gaston

Versions

Plots.jl version: v1.40.4
Backend version (]st -m <backend(s)>): v0.73.5
Output of versioninfo():

Julia Version 1.10.3
Commit 0b4590a5507 (2024-04-30 10:59 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (arm64-apple-darwin22.4.0)
  CPU: 10 × Apple M1 Pro
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, apple-m1)