random: return empty string instead of spinning when length is 0#63
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c-tonneslan wants to merge 1 commit into
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random: return empty string instead of spinning when length is 0#63c-tonneslan wants to merge 1 commit into
c-tonneslan wants to merge 1 commit into
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Random.String(0) allocates a zero-length result buffer and a zero-length read buffer, then enters the read loop. io.ReadFull on a 0-length slice returns immediately, the inner range loop does nothing, and the outer loop just spins forever without making progress. Easy to hit because the input type is uint8 so callers passing a variable can land on 0. Return "" up front when length is 0. Added a 0-length case to TestRandomString. Signed-off-by: Charlie Tonneslan <cst0520@gmail.com>
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`Random.String(0)` allocates a zero-length result buffer and a zero-length read buffer, then enters the read loop. `io.ReadFull` on a zero-length slice returns immediately, the inner range over the empty buffer does nothing, and the outer for-loop spins forever without making progress.
Easy to hit since the input type is `uint8` so any caller passing a length computed at runtime can land on 0.
```go
random.String(0) // hangs
```
Returns "" up front when `length == 0`. Added a 0-length case to `TestRandomString`.