From 72ffa1f308abe9d5926e872659418ab0a6396b37 Mon Sep 17 00:00:00 2001
From: Eliot Jones <elioty@hotmail.co.uk>
Date: Wed, 3 Jan 2018 19:17:12 +0000
Subject: [PATCH] make byte array input bytes behave correctly when seeking
 rather than forcing the consumer to work around it.

---
 src/UglyToad.Pdf/Fonts/TrueType/Tables/GlyphDataTable.cs      | 4 ++--
 src/UglyToad.Pdf/Fonts/TrueType/Tables/HeaderTable.cs         | 2 +-
 .../Fonts/TrueType/Tables/HorizontalHeaderTable.cs            | 2 +-
 .../Fonts/TrueType/Tables/IndexToLocationTable.cs             | 2 +-
 src/UglyToad.Pdf/Fonts/TrueType/Tables/MaximumProfileTable.cs | 2 +-
 src/UglyToad.Pdf/Fonts/TrueType/Tables/PostScriptTable.cs     | 2 +-
 src/UglyToad.Pdf/IO/ByteArrayInputBytes.cs                    | 2 +-
 7 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/GlyphDataTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/GlyphDataTable.cs
index eaf375f2..a04fbafa 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/GlyphDataTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/GlyphDataTable.cs
@@ -25,7 +25,7 @@
         public static GlyphDataTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, HeaderTable headerTable,
             IndexToLocationTable indexToLocationTable)
         {
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
 
             var offsets = indexToLocationTable.GlyphOffsets;
 
@@ -43,7 +43,7 @@
                     continue;
                 }
 
-                data.Seek(offsets[i] - 1 + table.Offset);
+                data.Seek(offsets[i] + table.Offset);
 
                 var contourCount = data.ReadSignedShort();
 
diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/HeaderTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/HeaderTable.cs
index 55aba610..86a95f2b 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/HeaderTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/HeaderTable.cs
@@ -87,7 +87,7 @@
 
         public static HeaderTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table)
         {
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
             var version = data.Read32Fixed();
             var fontRevision = data.Read32Fixed();
             var checkSumAdjustment = data.ReadUnsignedInt();
diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/HorizontalHeaderTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/HorizontalHeaderTable.cs
index 9cab098e..1c19b0ec 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/HorizontalHeaderTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/HorizontalHeaderTable.cs
@@ -99,7 +99,7 @@
 
         public static HorizontalHeaderTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table)
         {
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
             var majorVersion = data.ReadUnsignedShort();
             var minorVersion = data.ReadUnsignedShort();
 
diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/IndexToLocationTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/IndexToLocationTable.cs
index 062272d4..0b9c6b2e 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/IndexToLocationTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/IndexToLocationTable.cs
@@ -29,7 +29,7 @@
             const short shortFormat = 0;
             const short longFormat = 1;
 
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
 
             var format = headerTable.IndexToLocFormat;
 
diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/MaximumProfileTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/MaximumProfileTable.cs
index c55385f8..b665470c 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/MaximumProfileTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/MaximumProfileTable.cs
@@ -32,7 +32,7 @@
 
         public static BasicMaximumProfileTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table)
         {
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
 
             var version = data.Read32Fixed();
             var numberOfGlyphs = data.ReadUnsignedShort();
diff --git a/src/UglyToad.Pdf/Fonts/TrueType/Tables/PostScriptTable.cs b/src/UglyToad.Pdf/Fonts/TrueType/Tables/PostScriptTable.cs
index 1eed6050..51702bc7 100644
--- a/src/UglyToad.Pdf/Fonts/TrueType/Tables/PostScriptTable.cs
+++ b/src/UglyToad.Pdf/Fonts/TrueType/Tables/PostScriptTable.cs
@@ -81,7 +81,7 @@
 
         public static PostScriptTable Load(TrueTypeDataBytes data, TrueTypeHeaderTable table, BasicMaximumProfileTable maximumProfileTable)
         {
-            data.Seek(table.Offset - 1);
+            data.Seek(table.Offset);
             var formatType = data.Read32Fixed();
             var italicAngle = data.Read32Fixed();
             var underlinePosition = data.ReadSignedShort();
diff --git a/src/UglyToad.Pdf/IO/ByteArrayInputBytes.cs b/src/UglyToad.Pdf/IO/ByteArrayInputBytes.cs
index c2819066..ec680add 100644
--- a/src/UglyToad.Pdf/IO/ByteArrayInputBytes.cs
+++ b/src/UglyToad.Pdf/IO/ByteArrayInputBytes.cs
@@ -45,7 +45,7 @@
 
         public void Seek(long position)
         {
-            CurrentOffset = (int)position;
+            CurrentOffset = (int)position - 1;
             CurrentByte = CurrentOffset < 0 ? (byte)0 : bytes[CurrentOffset];
         }
     }