replace errors.go with github.com/pkg/errors (2/2) (#3890)

* init of (2/2) common errors

* Remove instances of cmn.Error (2/2)

- Replace usage of cmnError and errorWrap
- ref #3862

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* comment wording

* simplify IsErrXXX functions

* log panic along with stopping the MConnection

lite/errors/errors.go

@@ -3,7 +3,7 @@ package errors
 import (
 	"fmt"
 
-	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/pkg/errors"
 )
 
 //----------------------------------------
@@ -49,15 +49,12 @@ func (e errEmptyTree) Error() string {
 
 // ErrCommitNotFound indicates that a the requested commit was not found.
 func ErrCommitNotFound() error {
-	return cmn.ErrorWrap(errCommitNotFound{}, "")
+	return errors.Wrap(errCommitNotFound{}, "")
 }
 
 func IsErrCommitNotFound(err error) bool {
-	if err_, ok := err.(cmn.Error); ok {
-		_, ok := err_.Data().(errCommitNotFound)
-		return ok
-	}
-	return false
+	_, ok := errors.Cause(err).(errCommitNotFound)
+	return ok
 }
 
 //-----------------
@@ -65,18 +62,15 @@ func IsErrCommitNotFound(err error) bool {
 
 // ErrUnexpectedValidators indicates a validator set mismatch.
 func ErrUnexpectedValidators(got, want []byte) error {
-	return cmn.ErrorWrap(errUnexpectedValidators{
+	return errors.Wrap(errUnexpectedValidators{
 		got:  got,
 		want: want,
 	}, "")
 }
 
 func IsErrUnexpectedValidators(err error) bool {
-	if err_, ok := err.(cmn.Error); ok {
-		_, ok := err_.Data().(errUnexpectedValidators)
-		return ok
-	}
-	return false
+	_, ok := errors.Cause(err).(errUnexpectedValidators)
+	return ok
 }
 
 //-----------------
@@ -84,28 +78,22 @@ func IsErrUnexpectedValidators(err error) bool {
 
 // ErrUnknownValidators indicates that some validator set was missing or unknown.
 func ErrUnknownValidators(chainID string, height int64) error {
-	return cmn.ErrorWrap(errUnknownValidators{chainID, height}, "")
+	return errors.Wrap(errUnknownValidators{chainID, height}, "")
 }
 
 func IsErrUnknownValidators(err error) bool {
-	if err_, ok := err.(cmn.Error); ok {
-		_, ok := err_.Data().(errUnknownValidators)
-		return ok
-	}
-	return false
+	_, ok := errors.Cause(err).(errUnknownValidators)
+	return ok
 }
 
 //-----------------
 // ErrEmptyTree
 
 func ErrEmptyTree() error {
-	return cmn.ErrorWrap(errEmptyTree{}, "")
+	return errors.Wrap(errEmptyTree{}, "")
 }
 
 func IsErrEmptyTree(err error) bool {
-	if err_, ok := err.(cmn.Error); ok {
-		_, ok := err_.Data().(errEmptyTree)
-		return ok
-	}
-	return false
+	_, ok := errors.Cause(err).(errEmptyTree)
+	return ok
 }