all: fix issues spotted by nilness

In loader.matchPackagesInFS, the error check mismatched the used error.

Further down in the same func, a nil error case was impossible.

In builder.finish, a nil check on t would never be true.

Finally, in a test func, remove an impossible error comparison.

For more information on what this go/analysis pass does,
see https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/nilness.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: Ic648103c96435bb1339a15268e6204c44fe533f3
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1168432
Reviewed-by: Roger Peppe <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mvdan

cue/load/search.go

@@ -188,9 +188,9 @@ func (l *loader) matchPackagesInFS(pattern, pkgName string) *match {
 		// silently skipped as not matching the pattern.
 		// Do not take root, as we want to stay relative
 		// to one dir only.
-		relPath, e := filepath.Rel(c.Dir, path)
-		if e != nil {
-			panic(err) // Should never happen because c.Dir is absolute.
+		relPath, err2 := filepath.Rel(c.Dir, path)
+		if err2 != nil {
+			panic(err2) // Should never happen because c.Dir is absolute.
 		}
 		relPath = "./" + filepath.ToSlash(relPath)
 		// TODO: consider not doing these checks here.
@@ -199,8 +199,6 @@ func (l *loader) matchPackagesInFS(pattern, pkgName string) *match {
 		for _, p := range pkgs {
 			if err := p.Err; err != nil && (p == nil || len(p.InvalidFiles) == 0) {
 				switch err.(type) {
-				case nil:
-					break
 				case *NoFilesError:
 					if c.DataFiles && len(p.OrphanedFiles) > 0 {
 						break

encoding/openapi/build.go

@@ -1237,9 +1237,6 @@ func (b *builder) finish() *ast.StructLit {
 
 	default:
 		exprs := []ast.Expr{}
-		if t != nil {
-			exprs = append(exprs, (*ast.StructLit)(t))
-		}
 		for _, s := range b.allOf {
 			exprs = append(exprs, s)
 		}

tools/flow/flow_test.go

@@ -165,8 +165,7 @@ func taskFunc(v cue.Value) (flow.Runner, error) {
 				t.Fill(map[string]string{"stdout": "foo"})
 				return nil
 			}), nil
-		}
-		if err != nil && v.LookupPath(cue.MakePath(cue.Str("$id"))).Exists() {
+		} else if v.LookupPath(cue.MakePath(cue.Str("$id"))).Exists() {
 			return nil, err
 		}