Add a couple of reduced test-cases for PR 4259

PR 4259 fixed a large number of font bugs, but none of those where added as test-cases. This was, in my opinion, unfortunate since it increases the risk of regressions in the future when other font bugs are fixed.
This PR simply adds a few more test-cases, to improve our test coverage somewhat.

test/pdfs/.gitignore

@@ -34,6 +34,9 @@
 !issue918.pdf
 !issue1905.pdf
 !issue2833.pdf
+!issue2931.pdf
+!issue3323.pdf
+!issue4304.pdf
 !issue4550.pdf
 !rotated.pdf
 !issue1249.pdf

test/pdfs/issue4304.pdf

@@ -0,0 +1,78 @@
+%PDF-1.7
+101 0 obj
+<<
+/Type /Catalog
+/Pages 102 0 R
+>>
+endobj
+102 0 obj
+<<
+/Type /Pages
+/MediaBox [ 0 0 200 50 ]
+/Count 1
+/Kids [ 103 0 R ]
+>>
+endobj
+103 0 obj
+<<
+/Type /Page
+/Parent 102 0 R
+/Resources <<
+/Font <<
+/F1 104 0 R
+>>
+
+>>
+
+/Contents 105 0 R
+>>
+endobj
+104 0 obj
+<<
+/BaseFont /Times-Roman
+/Type /Font
+/Encoding 97 0 R
+/Subtype /Type1
+>>
+endobj
+105 0 obj
+<<
+/Length 74
+>>
+stream
+BT
+10 20 TD
+/F1 10 Tf
+(Words that should have spaces between them.) Tj
+ET
+endstream
+endobj
+97 0 obj
+<<
+/Type /Encoding
+/Differences [ 32 /.notdef 39 /quotesingle 145 /quoteleft /quoteright 150 /endash 232 /egrave /eacute 246 /odieresis 252 /udieresis ]
+>>
+endobj
+xref
+0 1
+0000000000 65535 f
+97 1
+0000000478 00000 n
+101 1
+0000000009 00000 n
+102 1
+0000000062 00000 n
+103 1
+0000000150 00000 n
+104 1
+0000000262 00000 n
+105 1
+0000000353 00000 n
+trailer
+<<
+/Size 6
+/Root 101 0 R
+>>
+startxref
+650
+%%EOF

test/test_manifest.json

@@ -863,6 +863,27 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue2931",
+       "file": "pdfs/issue2931.pdf",
+       "md5": "ea40940eaf3541b312bda9329167da11",
+       "link": false,
+       "rounds": 1,
+       "type": "eq"
+    },
+    {  "id": "issue3323",
+       "file": "pdfs/issue3323.pdf",
+       "md5": "1a14ff574013caeafa9d598269988764",
+       "link": false,
+       "rounds": 1,
+       "type": "eq"
+    },
+    {  "id": "issue4304",
+       "file": "pdfs/issue4304.pdf",
+       "md5": "1b1205bf0d7c1ad22a154b60da8e694d",
+       "link": false,
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "zerowidthline",
       "file": "pdfs/zerowidthline.pdf",
       "md5": "295d26e61a85635433f8e4b768953f60",