fix: error on empty array

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+name: Go package
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 'stable'
+
+      - name: Build
+        run: go build -v ./...

README.md

@@ -1,22 +1,17 @@
 go-shp
 ======
 
-[![Build Status](https://travis-ci.org/jonas-p/go-shp.svg?branch=master)](https://travis-ci.org/jonas-p/go-shp)
-[![Build status](https://ci.appveyor.com/api/projects/status/b64sntax4kxlouxa?svg=true)](https://ci.appveyor.com/project/fawick/go-shp)
-[![Go Report Card](https://goreportcard.com/badge/github.com/jonas-p/go-shp)](https://goreportcard.com/report/github.com/jonas-p/go-shp)
-[![Codevov](https://codecov.io/gh/jonas-p/go-shp/branch/master/graphs/badge.svg)](https://codecov.io/gh/jonas-p/go-shp)
+![Build status](https://github.com/karnott/go-shp/actions/workflows/build.yml/badge.svg)
+[![Go Report Card](https://goreportcard.com/badge/github.com/karnott/go-shp)](https://goreportcard.com/report/github.com/jonas-p/go-shp)
 
 Go library for reading and writing ESRI Shapefiles. This is a pure Golang implementation based on the ESRI Shapefile technical description.
 
 ### Usage
-#### Installation
-
-    go get github.com/jonas-p/go-shp
 
 #### Importing
 
 ```go
-import "github.com/jonas-p/go-shp"
+import "github.com/karnott/go-shp"
 ```
 
 ### Examples
@@ -83,5 +78,5 @@ for n, point := range points {
 
 ### Resources
 
-- [Documentation on godoc.org](http://godoc.org/github.com/jonas-p/go-shp)
+- [Documentation on godoc.org](http://godoc.org/github.com/karnott/go-shp)
 - [ESRI Shapefile Technical Description](http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf)

go.mod

@@ -0,0 +1,3 @@
+module github.com/karnott/go-shp
+
+go 1.20

sequentialreader.go

@@ -4,7 +4,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math"
 	"strings"
 )
@@ -81,19 +80,19 @@ func (sr *seqReader) readHeaders() {
 
 	er := &errReader{Reader: sr.shp}
 	// shp headers
-	io.CopyN(ioutil.Discard, er, 24)
+	io.CopyN(io.Discard, er, 24)
 	var l int32
 	binary.Read(er, binary.BigEndian, &l)
 	sr.filelength = int64(l) * 2
-	io.CopyN(ioutil.Discard, er, 4)
+	io.CopyN(io.Discard, er, 4)
 	binary.Read(er, binary.LittleEndian, &sr.geometryType)
 	sr.bbox.MinX = readFloat64(er)
 	sr.bbox.MinY = readFloat64(er)
 	sr.bbox.MaxX = readFloat64(er)
 	sr.bbox.MaxY = readFloat64(er)
-	io.CopyN(ioutil.Discard, er, 32) // skip four float64: Zmin, Zmax, Mmin, Max
+	io.CopyN(io.Discard, er, 32) // skip four float64: Zmin, Zmax, Mmin, Max
 	if er.e != nil {
-		sr.err = fmt.Errorf("Error when reading SHP header: %v", er.e)
+		sr.err = fmt.Errorf("error when reading SHP header: %v", er.e)
 		return
 	}
 
@@ -102,22 +101,22 @@ func (sr *seqReader) readHeaders() {
 	if sr.dbf == nil {
 		return
 	}
-	io.CopyN(ioutil.Discard, er, 4)
+	io.CopyN(io.Discard, er, 4)
 	binary.Read(er, binary.LittleEndian, &sr.dbfNumRecords)
 	binary.Read(er, binary.LittleEndian, &sr.dbfHeaderLength)
 	binary.Read(er, binary.LittleEndian, &sr.dbfRecordLength)
-	io.CopyN(ioutil.Discard, er, 20) // skip padding
+	io.CopyN(io.Discard, er, 20) // skip padding
 	numFields := int(math.Floor(float64(sr.dbfHeaderLength-33) / 32.0))
 	sr.dbfFields = make([]Field, numFields)
 	binary.Read(er, binary.LittleEndian, &sr.dbfFields)
 	buf := make([]byte, 1)
 	er.Read(buf[:])
 	if er.e != nil {
-		sr.err = fmt.Errorf("Error when reading DBF header: %v", er.e)
+		sr.err = fmt.Errorf("error when reading DBF header: %v", er.e)
 		return
 	}
 	if buf[0] != 0x0d {
-		sr.err = fmt.Errorf("Field descriptor array terminator not found")
+		sr.err = fmt.Errorf("field descriptor array terminator not found")
 		return
 	}
 	sr.dbfRow = make([]byte, sr.dbfRecordLength)
@@ -139,7 +138,7 @@ func (sr *seqReader) Next() bool {
 
 	if er.e != nil {
 		if er.e != io.EOF {
-			sr.err = fmt.Errorf("Error when reading shapefile header: %v", er.e)
+			sr.err = fmt.Errorf("error when reading shapefile header: %v", er.e)
 		} else {
 			sr.err = io.EOF
 		}
@@ -149,7 +148,7 @@ func (sr *seqReader) Next() bool {
 	var err error
 	sr.shape, err = newShape(shapetype)
 	if err != nil {
-		sr.err = fmt.Errorf("Error decoding shape type: %v", err)
+		sr.err = fmt.Errorf("error decoding shape type: %v", err)
 		return false
 	}
 	sr.shape.read(er)
@@ -160,25 +159,25 @@ func (sr *seqReader) Next() bool {
 		// iterating over all shapes.
 		er.e = nil
 	case er.e != nil:
-		sr.err = fmt.Errorf("Error while reading next shape: %v", er.e)
+		sr.err = fmt.Errorf("error while reading next shape: %v", er.e)
 		return false
 	}
 	skipBytes := int64(size)*2 + 8 - er.n
-	_, ce := io.CopyN(ioutil.Discard, er, skipBytes)
+	_, ce := io.CopyN(io.Discard, er, skipBytes)
 	if er.e != nil {
 		sr.err = er.e
 		return false
 	}
 	if ce != nil {
-		sr.err = fmt.Errorf("Error when discarding bytes on sequential read: %v", ce)
+		sr.err = fmt.Errorf("error when discarding bytes on sequential read: %v", ce)
 		return false
 	}
 	if _, err := io.ReadFull(sr.dbf, sr.dbfRow); err != nil {
-		sr.err = fmt.Errorf("Error when reading DBF row: %v", err)
+		sr.err = fmt.Errorf("error when reading DBF row: %v", err)
 		return false
 	}
-	if sr.dbfRow[0] != 0x20 && sr.dbfRow[0] != 0x2a {
-		sr.err = fmt.Errorf("Attribute row %d starts with incorrect deletion indicator", num)
+	if (len(sr.dbfRow) == 0) || (sr.dbfRow[0] != 0x20 && sr.dbfRow[0] != 0x2a) {
+		sr.err = fmt.Errorf("attribute row %d starts with incorrect deletion indicator", num)
 	}
 	return sr.err == nil
 }
@@ -212,8 +211,13 @@ func (sr *seqReader) Err() error {
 
 // Close closes the seqReader and free all the allocated resources.
 func (sr *seqReader) Close() error {
-	if err := sr.shp.Close(); err != nil {
-		return err
+	if sr.shp != nil {
+		if err := sr.shp.Close(); err != nil {
+			return err
+		}
+	}
+	if sr.dbf == nil {
+		return nil
 	}
 	if err := sr.dbf.Close(); err != nil {
 		return err

shapefile.go

@@ -2,6 +2,7 @@ package shp
 
 import (
 	"encoding/binary"
+	"errors"
 	"io"
 	"strings"
 )
@@ -29,6 +30,32 @@ const (
 	MULTIPATCH  ShapeType = 31
 )
 
+var shapeTypeNameMap = map[string]ShapeType{
+	"NULL":        NULL,
+	"POINT":       POINT,
+	"POLYLINE":    POLYLINE,
+	"POLYGON":     POLYGON,
+	"MULTIPOINT":  MULTIPOINT,
+	"POINTZ":      POINTZ,
+	"POLYLINEZ":   POLYLINEZ,
+	"POLYGONZ":    POLYGONZ,
+	"MULTIPOINTZ": MULTIPOINTZ,
+	"POINTM":      POINTM,
+	"POLYLINEM":   POLYLINEM,
+	"POLYGONM":    POLYGONM,
+	"MULTIPOINTM": MULTIPOINTM,
+	"MULTIPATCH":  MULTIPATCH,
+}
+
+// ParseShapeType tries to extract ShapeType from string
+func ParseShapeType(typ string) (ShapeType, error) {
+	t, ok := shapeTypeNameMap[strings.ToUpper(typ)]
+	if !ok {
+		return NULL, errors.New("invalid shape type")
+	}
+	return t, nil
+}
+
 // Box structure made up from four coordinates. This type
 // is used to represent bounding boxes
 type Box struct {
@@ -571,6 +598,23 @@ type Field struct {
 	Padding   [14]byte
 }
 
+const (
+	// TextFieldLength is default length for 'Text' geodatabase data type
+	TextFieldLength uint8 = 254
+	// FloatFieldLength is default length for 'Float' geodatabase data type
+	FloatFieldLength uint8 = 18
+	// FloatFieldPrecision is default precision for 'Float' geodatabase data type
+	FloatFieldPrecision uint8 = 8
+	// ShortFieldLength is default length for 'Short' geodatabase data type
+	ShortFieldLength uint8 = 10
+	// LongFieldLength is default length for 'Long' geodatabase data type
+	LongFieldLength uint8 = 18
+	// DateFieldLength is default length for 'Date' geodatabase data type
+	DateFieldLength uint8 = 8
+	// BoolFieldLength is default length for boolean data type
+	BoolFieldLength uint8 = 3
+)
+
 // Returns a string representation of the Field. Currently
 // this only returns field name.
 func (f Field) String() string {
@@ -606,7 +650,15 @@ func FloatField(name string, length uint8, precision uint8) Field {
 // DBF file. Used to store Date strings formatted as YYYYMMDD. Data wise this
 // is the same as a StringField with length 8.
 func DateField(name string) Field {
-	field := Field{Fieldtype: 'D', Size: 8}
+	field := Field{Fieldtype: 'D', Size: DateFieldLength}
 	copy(field.Name[:], []byte(name))
 	return field
 }
+
+// BoolField feturns a Field that can be used in SetFields to initialize the
+// DBF file. Used to store boolean values using "Yes"/"No" strings
+func BoolField(name string) Field {
+	field := Field{Fieldtype: 'C', Size: BoolFieldLength}
+	copy(field.Name[:], name)
+	return field
+}

zipreader.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"path"
+	"regexp"
 	"strings"
 )
 
@@ -71,8 +72,9 @@ func ShapesInZip(zipFilePath string) ([]string, error) {
 
 func shapesInZip(z *zip.ReadCloser) []*zip.File {
 	var shapeFiles []*zip.File
+	hiddenDirRegex := regexp.MustCompile("(?i)(__MACOSX|^\\.|\\/\\.)")
 	for _, f := range z.File {
-		if strings.HasSuffix(f.Name, ".shp") {
+		if strings.HasSuffix(f.Name, ".shp") && !hiddenDirRegex.MatchString(f.Name) {
 			shapeFiles = append(shapeFiles, f)
 		}
 	}