[dev.fuzz] internal/fuzz: avoid incorrect bytes modification during minimization
During minimization, the "canonical inputs" (vals) are updated
as viable minimized values are found. Previously, these bytes
could be changed later during minimization. This patch updates
the minimization code to revert the bytes back when a candidate
doesn't pass the minimization checks.
Another approach was in CL 340630 which would make a new allocation
each time a candidate was attempted. This will get very expensive
very quickly, as minimization can run several thousand times for every
new crash and every newly discovered interesting input.
Credit to Steven Johnstone (steven.james.johnstone@gmail.com) for the
"single_bytes" test which was added to minimize_test.go.
Fixes golang/go#47587
Change-Id: Ibd12f73458ed812bab7d3f1d4118854a54fc4d0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/348610
Trust: Katie Hockman <katie@golang.org>
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Katie Hockman <katie@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com>