Issue #51, Fix the issue with the column length mismatch

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/DbfStreamExtensions.cs

@@ -115,7 +115,7 @@ public static DbfField ReadDbaseFieldDescriptor(this Stream stream, Encoding enc
             }
             else if (type == DbfType.Date)
             {
-                return new DbfDateField(name);
+                return new DbfDateField(name, length);
             }
             else if (type == DbfType.Numeric)
             {
@@ -127,7 +127,7 @@ public static DbfField ReadDbaseFieldDescriptor(this Stream stream, Encoding enc
             }
             else if (type == DbfType.Logical)
             {
-                return new DbfLogicalField(name);
+                return new DbfLogicalField(name, length);
             }
             else
             {

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfDateField.cs

@@ -11,15 +11,16 @@ namespace NetTopologySuite.IO.Esri.Dbf.Fields
     /// </summary>
     public class DbfDateField : DbfField
     {
-        private static readonly int FieldLength = 8;           // This width is fixed and cannot be changed
+        private const int FieldLength = 8;           // This width is fixed and cannot be changed
         private static readonly string DateFormat = "yyyyMMdd";
 
         /// <summary>
         ///  Initializes a new instance of the field class.
         /// </summary>
         /// <param name="name">Field name.</param>
-        public DbfDateField(string name)
-            : base(name, DbfType.Date, FieldLength, 0)
+        /// <param name="length">Field length.</param>
+        public DbfDateField(string name, int length = FieldLength)
+            : base(name, DbfType.Date, length, 0)
         {
         }
 

src/NetTopologySuite.IO.Esri.Shapefile/Dbf/Fields/DbfLogicalField.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Text;
 
 namespace NetTopologySuite.IO.Esri.Dbf.Fields
 {
@@ -12,7 +13,7 @@ public class DbfLogicalField : DbfField
         private readonly static byte DefaultValue = (byte)' '; // (byte)'?'; Initialized to 0x20 (space) otherwise T or F (http://www.dbase.com/KnowledgeBase/int/db7_file_fmt.htm)
         private readonly static byte TrueValue = (byte)'T';
         private readonly static byte FalseValue = (byte)'F';
-        private readonly static int FieldLength = 1;        // This width is fixed and cannot be changed
+        private const int FieldLength = 1;        // This width is fixed and cannot be changed
 
         private readonly static string TrueValues = "TtYy";
         private readonly static string FalseValues = "FfNn";
@@ -22,8 +23,9 @@ public class DbfLogicalField : DbfField
         ///  Initializes a new instance of the field class.
         /// </summary>
         /// <param name="name">Field name.</param>
-        public DbfLogicalField(string name)
-            : base(name, DbfType.Logical, FieldLength, 0)
+        /// <param name="length">Field length.</param>
+        public DbfLogicalField(string name, int length = FieldLength)
+            : base(name, DbfType.Logical, length, 0)
         {
         }
 
@@ -44,13 +46,22 @@ public override object Value
 
         internal override void ReadValue(Stream stream)
         {
-            var logicalValue = stream.ReadByteChar();
+            // Logic column should have a Length of 1. However, some data providers produce shapfiles with a length greater than 1.
+            // Handle also those not specification compliant cases.
+            var logicalValueString = stream.ReadString(Length, Encoding.ASCII)?.Trim();
+            if (string.IsNullOrEmpty(logicalValueString))
+            {
+                LogicalValue = null;
+                return;
+            }
+
+            var logicalValueChar = logicalValueString[0];
 
-            if (TrueValues.Contains(logicalValue))
+            if (TrueValues.Contains(logicalValueChar))
             {
                 LogicalValue = true;
             }
-            else if (FalseValues.Contains(logicalValue))
+            else if (FalseValues.Contains(logicalValueChar))
             {
                 LogicalValue = false;
             }
@@ -78,7 +89,4 @@ internal override void WriteValue(Stream stream)
         }
 
     }
-
-
-
 }

test/NetTopologySuite.IO.Esri.Test/Issues/Issue051.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using System.Linq;
+using NetTopologySuite.Features;
+using NetTopologySuite.IO.Esri.Dbf;
+using NUnit.Framework;
+
+namespace NetTopologySuite.IO.Esri.Test.Issues
+{
+    /// <summary>
+    /// https://github.com/NetTopologySuite/NetTopologySuite.IO.Esri/issues/51
+    /// </summary>
+    internal class Issue051
+    {
+        [Test]
+        public void Read_When_ColumnLengthMissmatch()
+        {
+            var shpPath = TestShapefiles.PathTo("#51-columnLengthMissmatch.dbf");
+            List<IAttributesTable> attributes = null;
+            Assert.DoesNotThrow(() =>
+            {
+                var dbfReader = new DbfReader(shpPath);
+                attributes = dbfReader.ToList();
+            });
+
+            Assert.NotNull(attributes);
+
+            //First row is null and empty
+            Assert.AreEqual(string.Empty, attributes[0]["RoadLinkId"]);
+            Assert.AreEqual(null, attributes[0]["Tunnel"]);
+            Assert.AreEqual(null, attributes[0]["Bridge"]);
+            Assert.AreEqual(null, attributes[0]["CarAccess"]);
+            Assert.AreEqual(null, attributes[0]["Walk"]);
+            Assert.AreEqual(null, attributes[0]["MF_4_7"]);
+            Assert.AreEqual(null, attributes[0]["COREID"]);
+
+            //Second row has value but length is missmatch in each column
+            Assert.AreEqual("osgb4000000080908489", attributes[1]["RoadLinkId"]);
+            Assert.AreEqual(true, attributes[1]["Tunnel"]);
+            Assert.AreEqual(false, attributes[1]["Bridge"]);
+            Assert.AreEqual(true, attributes[1]["CarAccess"]);
+            Assert.AreEqual(4.8, attributes[1]["Walk"]);
+            Assert.AreEqual(50, attributes[1]["MF_4_7"]);
+            Assert.AreEqual(55483, attributes[1]["COREID"]);
+        }
+    }
+}