Fix SmallCStr conversion from CStr

[ehuss]

The conversion from CStr to SmallCStr was not including the null byte. SmallCStr requires a trailing null. This caused as_c_str to either panic if std is built with debug assertions, or to have some corrupt memory behavior.

[rustbot]

r? @davidtwco

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[Mark-Simulacrum]

@bors r+ p=1

[bors]

📌 Commit 217e5e4 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit 217e5e4 with merge bd6b336...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing bd6b336 to master...

[rust-timer]

Finished benchmarking commit (bd6b336): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.4%	[1.4%, 1.4%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 636.575s -> 636.704s (0.02%)
Artifact size: 306.16 MiB -> 306.15 MiB (-0.00%)