Improvments based on review

- Moved returns into the default section of switch statement that can
  only happen then.

- Fix typo.

storage/local/chunk.go

@@ -285,7 +285,7 @@ type chunkIterator interface {
 	// of the find... methods). It returns ZeroSamplePair before any of
 	// those methods were called.
 	value() model.SamplePair
-	// Returns the last error encountered. In general, an error signal data
+	// Returns the last error encountered. In general, an error signals data
 	// corruption in the chunk and requires quarantining.
 	err() error
 }

storage/local/delta.go

@@ -328,8 +328,8 @@ func (acc *deltaEncodedIndexAccessor) timestampAtIndex(idx int) model.Time {
 		return model.Time(binary.LittleEndian.Uint64(acc.c[offset:]))
 	default:
 		acc.lastErr = fmt.Errorf("invalid number of bytes for time delta: %d", acc.tBytes)
+		return model.Earliest
 	}
-	return model.Earliest
 }
 
 func (acc *deltaEncodedIndexAccessor) sampleValueAtIndex(idx int) model.SampleValue {
@@ -358,7 +358,7 @@ func (acc *deltaEncodedIndexAccessor) sampleValueAtIndex(idx int) model.SampleVa
 			return model.SampleValue(math.Float64frombits(binary.LittleEndian.Uint64(acc.c[offset:])))
 		default:
 			acc.lastErr = fmt.Errorf("invalid number of bytes for floating point delta: %d", acc.vBytes)
+			return 0
 		}
 	}
-	return 0
 }

storage/local/doubledelta.go

@@ -452,8 +452,8 @@ func (acc *doubleDeltaEncodedIndexAccessor) timestampAtIndex(idx int) model.Time
 		return model.Time(binary.LittleEndian.Uint64(acc.c[offset:]))
 	default:
 		acc.lastErr = fmt.Errorf("invalid number of bytes for time delta: %d", acc.tBytes)
+		return model.Earliest
 	}
-	return model.Earliest
 }
 
 func (acc *doubleDeltaEncodedIndexAccessor) sampleValueAtIndex(idx int) model.SampleValue {
@@ -491,6 +491,7 @@ func (acc *doubleDeltaEncodedIndexAccessor) sampleValueAtIndex(idx int) model.Sa
 		// No d8 for ints.
 		default:
 			acc.lastErr = fmt.Errorf("invalid number of bytes for integer delta: %d", acc.vBytes)
+			return 0
 		}
 	} else {
 		switch acc.vBytes {
@@ -503,7 +504,7 @@ func (acc *doubleDeltaEncodedIndexAccessor) sampleValueAtIndex(idx int) model.Sa
 			return model.SampleValue(math.Float64frombits(binary.LittleEndian.Uint64(acc.c[offset:])))
 		default:
 			acc.lastErr = fmt.Errorf("invalid number of bytes for floating point delta: %d", acc.vBytes)
+			return 0
 		}
 	}
-	return 0
 }