Add test for bad data and bad datafile

TODO

@@ -61,7 +61,7 @@ Make sure pages tree repair generates warnings.
 * Have a test case if possible that exercises the object description
   which means we need some kind of semantic error that gets caught
   after creation.
-* Test invalid data, invalid data file
+* Document that /Length is ignored in stream dictionary replacements
 
 Try to never flatten pages tree. Make sure we do something reasonable
 with pages tree repair. The problem is that if pages tree repair is

libqpdf/QPDFWriter.cc

@@ -1419,14 +1419,21 @@ QPDFWriter::willFilterStream(
         pushPipeline(new Pl_Buffer("stream data"));
         PipelinePopper pp_stream_data(this, stream_data);
         activatePipelineStack(pp_stream_data);
-        filtered = stream.pipeStreamData(
-            this->m->pipeline,
-            (((filter && normalize) ? qpdf_ef_normalize : 0) |
-             ((filter && compress_stream) ? qpdf_ef_compress : 0)),
-            (filter ? (uncompress ? qpdf_dl_all : this->m->stream_decode_level)
-                    : qpdf_dl_none),
-            false,
-            (attempt == 1));
+        try {
+            filtered = stream.pipeStreamData(
+                this->m->pipeline,
+                (((filter && normalize) ? qpdf_ef_normalize : 0) |
+                 ((filter && compress_stream) ? qpdf_ef_compress : 0)),
+                (filter
+                     ? (uncompress ? qpdf_dl_all : this->m->stream_decode_level)
+                     : qpdf_dl_none),
+                false,
+                (attempt == 1));
+        } catch (std::runtime_error& e) {
+            throw std::runtime_error(
+                "error while getting stream data for " + stream.unparse() +
+                ": " + e.what());
+        }
         if (filter && (!filtered)) {
             // Try again
             filter = false;

qpdf/qtest/qpdf-json.test

@@ -33,6 +33,8 @@ my @badfiles = (
     'missing-trailer',
     'missing-objects',
     'obj-key-errors',
+    'bad-data',
+    'bad-datafile',
     );
 
 $n_tests += scalar(@badfiles);

qpdf/qtest/qpdf/qjson-bad-data.json

@@ -0,0 +1,68 @@
+{
+  "qpdf-v2": {
+    "pdfversion": "1.3",
+    "maxobjectid": 6,
+    "objects": {
+      "obj:1 0 R": {
+        "value": {
+          "/Pages": "2 0 R",
+          "/Type": "/Catalog"
+        }
+      },
+      "obj:2 0 R": {
+        "value": {
+          "/Count": 1,
+          "/Kids": [
+            "3 0 R"
+          ],
+          "/Type": "/Pages"
+        }
+      },
+      "obj:3 0 R": {
+        "value": {
+          "/Contents": ["4 0 R", "7 0 R"],
+          "/MediaBox": [
+            0,
+            0,
+            612,
+            792
+          ],
+          "/Parent": "2 0 R",
+          "/Resources": {
+            "/Font": {
+              "/F1": "6 0 R"
+            },
+            "/ProcSet": "5 0 R"
+          },
+          "/Type": "/Page"
+        }
+      },
+      "obj:4 0 R": {
+        "stream": {
+          "data": "@not-base64@",
+          "dict": {}
+        }
+      },
+      "obj:5 0 R": {
+        "value": [
+          "/PDF",
+          "/Text"
+        ]
+      },
+      "obj:6 0 R": {
+        "value": {
+          "/BaseFont": "/Helvetica",
+          "/Encoding": "/WinAnsiEncoding",
+          "/Subtype": "/Type1",
+          "/Type": "/Font"
+        }
+      },
+      "trailer": {
+        "value": {
+          "/Root": "1 0 R",
+          "/Size": 7
+        }
+      }
+    }
+  }
+}

qpdf/qtest/qpdf/qjson-bad-data.out

@@ -0,0 +1 @@
+qpdf: error while getting stream data for 4 0 R: base64-decode: base64 decode: invalid input

qpdf/qtest/qpdf/qjson-bad-datafile.json

@@ -0,0 +1,68 @@
+{
+  "qpdf-v2": {
+    "pdfversion": "1.3",
+    "maxobjectid": 6,
+    "objects": {
+      "obj:1 0 R": {
+        "value": {
+          "/Pages": "2 0 R",
+          "/Type": "/Catalog"
+        }
+      },
+      "obj:2 0 R": {
+        "value": {
+          "/Count": 1,
+          "/Kids": [
+            "3 0 R"
+          ],
+          "/Type": "/Pages"
+        }
+      },
+      "obj:3 0 R": {
+        "value": {
+          "/Contents": ["4 0 R", "7 0 R"],
+          "/MediaBox": [
+            0,
+            0,
+            612,
+            792
+          ],
+          "/Parent": "2 0 R",
+          "/Resources": {
+            "/Font": {
+              "/F1": "6 0 R"
+            },
+            "/ProcSet": "5 0 R"
+          },
+          "/Type": "/Page"
+        }
+      },
+      "obj:4 0 R": {
+        "stream": {
+          "datafile": "file does not exist",
+          "dict": {}
+        }
+      },
+      "obj:5 0 R": {
+        "value": [
+          "/PDF",
+          "/Text"
+        ]
+      },
+      "obj:6 0 R": {
+        "value": {
+          "/BaseFont": "/Helvetica",
+          "/Encoding": "/WinAnsiEncoding",
+          "/Subtype": "/Type1",
+          "/Type": "/Font"
+        }
+      },
+      "trailer": {
+        "value": {
+          "/Root": "1 0 R",
+          "/Size": 7
+        }
+      }
+    }
+  }
+}

qpdf/qtest/qpdf/qjson-bad-datafile.out

@@ -0,0 +1 @@
+qpdf: error while getting stream data for 4 0 R: open file does not exist: No such file or directory