Handling for corrupt files.

1. Some files the ObjectStream may not be referred from the XRefStm.
2. Some objects like fonts etc. may not be available. In that case, PDFDocEncoding is assumed.

Author: sambitdash

src/CosDoc.jl

@@ -150,7 +150,8 @@ end
 cosDocGetObject(doc::CosDocImpl, obj::CosObject) = obj
 
 function cosDocGetObject(doc::CosDocImpl, ref::CosIndirectObjectRef)
-    locObj = doc.xref[ref]
+    locObj = get(doc.xref, ref, CosObjectLoc(-1))
+    locObj.loc == -1 && return CosNull
     return cosDocGetObject(doc, locObj.stm, ref, locObj)
 end
 
@@ -165,13 +166,14 @@ function cosDocGetObject(doc::CosDocImpl, stm::CosNullType,
 end
 
 function cosDocGetObject(doc::CosDocImpl, stmref::CosIndirectObjectRef,
-  ref::CosIndirectObjectRef, locObj::CosObjectLoc)
-  objstm = cosDocGetObject(doc, stmref)
-  if (locObj.obj == CosNull)
-    locObj.obj = cosObjectStreamGetObject(objstm, ref, locObj.loc)
-    attach_object(doc, locObj.obj)
-  end
-  return locObj.obj
+                         ref::CosIndirectObjectRef, locObj::CosObjectLoc)
+    objstm = cosDocGetObject(doc, stmref)
+    (objstm === CosNull) && return CosNull
+    if (locObj.obj == CosNull)
+        locObj.obj = cosObjectStreamGetObject(objstm, ref, locObj.loc)
+        attach_object(doc, locObj.obj)
+    end
+    return locObj.obj
 end
 
 function read_header(ps)
@@ -234,6 +236,7 @@ function doc_trailer_update(ps::BufferedInputStream, doc::CosDocImpl)
 
     if doc.isPDF
         seek(ps, doc.startxref)
+        chomp_space!(ps)
         doc.hasNativeXRefStm = (may_have_xrefstream(doc) && ispdfdigit(peek(ps)))
         (doc.hasNativeXRefStm) ? read_xref_streams(ps, doc) : read_xref_tables(ps, doc)
     end

src/PDPage.jl

@@ -159,7 +159,7 @@ function page_find_font(page::PDPageImpl, fontname::CosName)
     cosdoc = page.doc.cosDoc
     pgnode = page.cospage
 
-    while font === CosNull || pgnode !== CosNull
+    while font === CosNull && pgnode !== CosNull
         resref = get(pgnode, cn"Resources")
         resources = cosDocGetObject(cosdoc, resref)
         if resources !== CosNull
@@ -175,5 +175,7 @@ function page_find_font(page::PDPageImpl, fontname::CosName)
     return font
 end
 
+get_encoded_string(s::CosString, fontname::CosNullType, page::PDPage) = CDTextString(s)
+
 get_encoded_string(s::CosString, fontname::CosName, page::PDPage) =
     get_encoded_string(s, get(page.fums, fontname, nothing))

src/PDPageElement.jl

@@ -472,7 +472,7 @@ function showtext(io::IO, grp::PDPageObjectGroup, state::Dict=Dict())
 end
 
 function showtext(io::IO, tr::PDPageTextRun, state::Dict=Dict())
-    fontname, font = get(state, :font, CosNull)
+    fontname, font = get(state, :font, (CosNull, CosNull))
     page = get(state, :page, CosNull)
     for s in tr.ss
         text = get_encoded_string(s, fontname, page)