fix a bug with font reading order in multi-page documents

src/UglyToad.Pdf.Tests/Integration/FarmerMacTests.cs

@@ -0,0 +1,39 @@
+namespace UglyToad.Pdf.Tests.Integration
+{
+    using System;
+    using System.IO;
+    using Xunit;
+
+    public class FarmerMacTests
+    {
+        private static string GetFilename()
+        {
+            var documentFolder = Path.GetFullPath(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "..", "..", "..", "Integration", "Documents"));
+
+            return Path.Combine(documentFolder, "FarmerMac.pdf");
+        }
+
+        [Fact]
+        public void HasCorrectNumberOfPages()
+        {
+            using (var document = PdfDocument.Open(GetFilename()))
+            {
+                Assert.Equal(5, document.NumberOfPages);
+            }
+        }
+
+        [Fact]
+        public void HasCorrectContentAfterReadingPreviousPage()
+        {
+            using (var document = PdfDocument.Open(GetFilename()))
+            {
+                // ReSharper disable once RedundantAssignment
+                var page = document.GetPage(1);
+                page = document.GetPage(2);
+
+                Assert.Contains("financial results for the fiscal quarter ended June 30, 2017 and (2) a conference call to discuss those results and Farmer Mac", page.Text);
+            }
+        }
+
+    }
+}

src/UglyToad.Pdf.Tests/Integration/SwedishTouringCarChampionshipTests.cs

@@ -17,9 +17,7 @@
         [Fact]
         public void HasCorrectNumberOfPages()
         {
-            var file = GetFilename();
+            using (var document = PdfDocument.Open(GetFilename()))
-
-            using (var document = PdfDocument.Open(File.ReadAllBytes(file)))
             {
                 Assert.Equal(4, document.NumberOfPages);
             }
@@ -61,14 +59,5 @@
                 Assert.Contains("Söderberg", page.Text);
             }
         }
-
-        //[Fact]
-        //public void localFileTest()
-        //{
-        //    using (var document = PdfDocument.Open(@"C:\Users\eliot\Downloads\Document (1).pdf"))
-        //    {
-        //        var page = document.GetPage(1);
-        //    }
-        //}
     }
 }

src/UglyToad.Pdf.Tests/UglyToad.Pdf.Tests.csproj

@@ -10,6 +10,7 @@
   <ItemGroup>
     <None Remove="Fonts\TrueType\google-simple-doc.ttf" />
     <None Remove="Fonts\TrueType\Roboto-Regular.ttf" />
+    <None Remove="Integration\Documents\FarmerMac.pdf" />
     <None Remove="Integration\Documents\Font Size Test - from google chrome print pdf.pdf" />
     <None Remove="Integration\Documents\Font Size Test - from libre office.pdf" />
     <None Remove="Integration\Documents\Judgement Document.pdf" />
@@ -29,6 +30,9 @@
     <EmbeddedResource Include="Fonts\TrueType\Roboto-Regular.ttf">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </EmbeddedResource>
+    <Content Include="Integration\Documents\FarmerMac.pdf">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
     <Content Include="Integration\Documents\Font Size Test - from libre office.pdf">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>

src/UglyToad.Pdf/Content/ResourceContainer.cs

@@ -14,7 +14,8 @@
         private readonly IPdfObjectParser pdfObjectParser;
         private readonly IFontFactory fontFactory;
 
-        private readonly Dictionary<CosName, IFont> loadedFonts = new Dictionary<CosName, IFont>();
+        private readonly Dictionary<IndirectReference, IFont> loadedFonts = new Dictionary<IndirectReference, IFont>();
+        private readonly Dictionary<CosName, IndirectReference> currentResourceState = new Dictionary<CosName, IndirectReference>();
 
         public ResourceContainer(IPdfObjectParser pdfObjectParser, IFontFactory fontFactory)
         {
@@ -57,11 +58,6 @@
         {
             foreach (var pair in fontDictionary)
             {
-                if (loadedFonts.ContainsKey(pair.Key))
-                {
-                    continue;
-                }
-
                 if (!(pair.Value is CosObject objectKey))
                 {
                     if (isLenientParsing)
@@ -72,6 +68,15 @@
                     throw new InvalidOperationException($"The font with name {pair.Key} did not link to an object key. Value was: {pair.Value}.");
                 }
 
+                var reference = objectKey.ToIndirectReference();
+
+                currentResourceState[pair.Key] = reference;
+
+                if (loadedFonts.ContainsKey(reference))
+                {
+                    continue;
+                }
+                
                 var fontObject = DirectObjectFinder.Find<PdfDictionary>(objectKey, pdfObjectParser, reader, false);
 
                 if (fontObject == null)
@@ -79,13 +84,15 @@
                     throw new InvalidOperationException($"Could not retrieve the font with name: {pair.Key} which should have been object {objectKey.GetObjectNumber()}");
                 }
 
-                loadedFonts[pair.Key] = fontFactory.Get(fontObject, reader, isLenientParsing);
+                loadedFonts[reference] = fontFactory.Get(fontObject, reader, isLenientParsing);
             }
         }
         
         public IFont GetFont(CosName name)
         {
-            loadedFonts.TryGetValue(name, out var font);
+            var reference = currentResourceState[name];
+
+            loadedFonts.TryGetValue(reference, out var font);
 
             return font;
         }