This CL introduces two vet checks. Statistics and code below are from a recent 50mb corpus of public code.
1. Check for redundant conjunctions and disjunctions. This check caught 26 instances, of which 20 were clearly copy/paste bugs and 6 appeared to be mere duplication. A typical example:
if xResolution < 0 || xResolution < 0 {
panic("SetSize(): width < 0 || height < 0")
}
2. Check for expressions of the form 'x != c1 || x != c2' or 'x == c1 && x == c2', with c1 and c2 constant expressions. This check caught 16 instances, of which all were bugs. A typical example:
if rf.uri.Scheme != "http" || rf.uri.Scheme != "ftp" {
rf.uri.Scheme = "file"
}
Fixesgolang/go#7622.
LGTM=rsc, r
R=golang-codereviews, jscrockett01, r, gri, rsc
CC=golang-codereviews
https://golang.org/cl/98120043
