When content stream is compressed using bad flate data, trying to extract

as much data as possible and show some results.

Author: sambitdash

src/Inflate.jl

@@ -69,7 +69,7 @@ _inflate(stm::z_stream) =
     ccall((:inflate, libz), Cint, (Ref{z_stream}, Cint), stm, 0)
 
 function inflate(io::IO)
-    CHUNK = 16384
+    CHUNK = 262144
 
     iob = IOBuffer()
 
@@ -92,10 +92,13 @@ function inflate(io::IO)
                 strm.next_out = pointer(oub)
                 ret = _inflate(strm)
                 ret == Z_STREAM_ERROR && error("zlib stream state clobbered")
-                ret != Z_OK && ret != Z_STREAM_END && _zerror(ret)
+                ret == Z_DATA_ERROR && @warn "invalid or incomplete inflate data"
+                ret != Z_OK && ret != Z_STREAM_END && ret != Z_DATA_ERROR &&
+                    _zerror(ret)
                 have = CHUNK - strm.avail_out
                 resize!(oub, have)
                 write(iob, oub)
+                (ret == Z_STREAM_END || ret == Z_DATA_ERROR) && break
                 resize!(oub, CHUNK)
             end
         end
@@ -108,7 +111,6 @@ end
 function _zerror(ret::Cint)
     msg =
         ret == Z_STREAM_ERROR  ? "invalid compression level" :
-        ret == Z_DATA_ERROR    ? "invalid or incomplete deflate data" :
         ret == Z_MEM_ERROR     ? "out of memory" :
         ret == Z_VERSION_ERROR ? "zlib version mismatch!" :
                                  "zlib internal error"

test/runtests.jl

@@ -13,7 +13,7 @@ using PDFIO.Common: read_pkcs12
 
 include("debugIO.jl")
 
-pdftest_ver  = "0.0.7"
+pdftest_ver  = "0.0.8"
 pdftest_link = "https://github.com/sambitdash/PDFTest/archive/v"*pdftest_ver
 
 zipfile = "pdftest-"*pdftest_ver
@@ -273,6 +273,24 @@ end
             pdDocClose(doc)
             length(utilPrintOpenFiles()) == 0
         end
+        @test begin
+            # Corrupt deflate stream
+            filename="00007.pdf"
+            DEBUG && println(filename)
+            resfile, template, filename = local_testfiles(filename)
+            doc = pdDocOpen(filename)
+            io = util_open(resfile, "w")
+            @info "Begin testing corrupt flate"
+            try
+                extract_text(io, doc)
+            finally
+                util_close(io)
+                pdDocClose(doc)
+            end
+            @info "End testing corrupt flate"
+            @test files_equal(resfile, template)
+            length(utilPrintOpenFiles()) == 0
+        end
     end
     @testset "Document without Info" begin
         @test begin