light: handle too high errors correctly (#6346)

CHANGELOG_PENDING.md

@@ -87,3 +87,4 @@ Friendly reminder: We have a [bug bounty program](https://hackerone.com/tendermi
 - [privval] \#5638 Increase read/write timeout to 5s and calculate ping interval based on it (@JoeKash)
 - [blockchain/v1] [\#5701](https://github.com/tendermint/tendermint/pull/5701) Handle peers without blocks (@melekes)
 - [blockchain/v1] \#5711 Fix deadlock (@melekes)
+- [light] \#6346 Correctly handle too high errors to improve client robustness (@cmwaters)

light/client.go

@@ -731,7 +731,7 @@ func (c *Client) verifySkipping(
 					blockCache = append(blockCache, interimBlock)
 
 				// if the error is benign, the client does not need to replace the primary
-				case provider.ErrLightBlockNotFound, provider.ErrNoResponse:
+				case provider.ErrLightBlockNotFound, provider.ErrNoResponse, provider.ErrHeightTooHigh:
 					return nil, err
 
 				// all other errors such as ErrBadLightBlock or ErrUnreliableProvider are seen as malevolent and the
@@ -969,7 +969,7 @@ func (c *Client) lightBlockFromPrimary(ctx context.Context, height int64) (*type
 		// Everything went smoothly. We reset the lightBlockRequests and return the light block
 		return l, nil
 
-	case provider.ErrNoResponse, provider.ErrLightBlockNotFound:
+	case provider.ErrNoResponse, provider.ErrLightBlockNotFound, provider.ErrHeightTooHigh:
 		// we find a new witness to replace the primary
 		c.logger.Debug("error from light block request from primary, replacing...",
 			"error", err, "height", height, "primary", c.primary)
@@ -1072,7 +1072,7 @@ func (c *Client) findNewPrimary(ctx context.Context, height int64, remove bool)
 			return response.lb, nil
 
 		// process benign errors by logging them only
-		case provider.ErrNoResponse, provider.ErrLightBlockNotFound:
+		case provider.ErrNoResponse, provider.ErrLightBlockNotFound, provider.ErrHeightTooHigh:
 			lastError = response.err
 			c.logger.Debug("error on light block request from witness",
 				"error", response.err, "primary", c.witnesses[response.witnessIndex])