Fix bugzilla 24832 - Segfault in hex string

[dkorpel]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	24832	normal	Segfault in hex string

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "stable + dmd#17024"