Properly detect when .pdb file use the new Portable PDB format

Author: jairbubbles

src/GitLink/GitLink.csproj

@@ -75,6 +75,7 @@
     <Compile Include="Pdb\PdbStream.cs" />
     <Compile Include="Pdb\SrcSrv.cs" />
     <Compile Include="Pdb\SrcSrvContext.cs" />
+    <Compile Include="Helpers\PortablePdbHelper.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Providers\BitBucketProvider.cs" />

src/GitLink/Helpers/PortablePdbHelper.cs

@@ -0,0 +1,55 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="PortablePdbHelper.cs" company="CatenaLogic">
+//   Copyright (c) 2014 - 2016 CatenaLogic. All rights reserved.
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace GitLink
+{
+    using System.IO;
+
+    internal static class PortablePdbHelper
+    {
+        /// <summary>
+        /// Is the given .pdb using the new Portable format ? (https://github.com/dotnet/corefx/blob/master/src/System.Reflection.Metadata/specs/PortablePdb-Metadata.md)
+        /// </summary>
+        /// <param name="pdbPath">.pdb file path</param>
+        /// <returns>Returns if it's a Portable PDB</returns>
+        public static bool IsPortablePdb(string pdbPath)
+        {
+            using (var fs = File.Open(pdbPath, FileMode.Open, FileAccess.Read))
+            using (var br = new BinaryReader(fs))
+            {
+                // More infos in chapter II.24.2 of ECMA-335 (http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-335.pdf)
+                var signature = 0x424A5342;
+                if (br.ReadUInt32() != signature)
+                {
+                    return false;
+                }
+
+                var majorVersion = br.ReadUInt16();
+                if (majorVersion != 1)
+                {
+                    return false;
+                }
+
+                var minorVersion = br.ReadUInt16();
+                if (minorVersion != 1)
+                {
+                    return false;
+                }
+
+                var reserved = br.ReadUInt32();
+                if (reserved != 0)
+                {
+                    return false;
+                }
+
+                var versionLength = br.ReadUInt32();
+                var version = System.Text.Encoding.UTF8.GetString(br.ReadBytes((int)versionLength));
+
+                return version.StartsWith("PDB v1.0");
+            }
+        }
+    }
+}

src/GitLink/Linker.cs

@@ -50,6 +50,12 @@ public static class Linker
                 }
             }
 
+            if (PortablePdbHelper.IsPortablePdb(pdbPath))
+            {
+                Log.Warning("Portable PDB format is not compatible with GitLink. Please use SourceLink (https://github.com/ctaggart/SourceLink).");
+                return true;
+            }
+
             if (options.IndexAllDepotFiles)
             {
                 if (repositoryDirectory == null)