Update docs and prepare QPDF::writeJSON for changes

Add additional parameters that will be needed to call QPDF::writeJSON
in partial mode.

4 files changed, 21 insertions, 10 deletions

diff --git a/libqpdf/QPDFJob.cc b/libqpdf/QPDFJob.cc
index 06e93704..ae717218 100644
--- a/libqpdf/QPDFJob.cc
+++ b/libqpdf/QPDFJob.cc
@@ -3381,6 +3381,8 @@ QPDFJob::writeJSON(QPDF& pdf)
     pdf.writeJSON(
         this->m->json_output,
         fp.get(),
+        true,
+        true,
         this->m->decode_level,
         this->m->json_stream_data,
         file_prefix,
diff --git a/libqpdf/QPDFJob_config.cc b/libqpdf/QPDFJob_config.cc
index 0192346e..6a500b5c 100644
--- a/libqpdf/QPDFJob_config.cc
+++ b/libqpdf/QPDFJob_config.cc
@@ -312,6 +312,9 @@ QPDFJob::Config::jsonOutput(std::string const& parameter)
     if (!o.m->decode_level_set) {
         o.m->decode_level = qpdf_dl_none;
     }
+    if (o.m->json_keys.empty()) {
+        o.m->json_keys.insert("qpdf");
+    }
     return this;
 }
 
diff --git a/libqpdf/QPDF_json.cc b/libqpdf/QPDF_json.cc
index 59aac05e..81f21f8a 100644
--- a/libqpdf/QPDF_json.cc
+++ b/libqpdf/QPDF_json.cc
@@ -764,6 +764,8 @@ void
 QPDF::writeJSON(
     int version,
     Pipeline* p,
+    bool complete,
+    bool first_key,
     qpdf_stream_decode_level_e decode_level,
     qpdf_json_stream_data_e json_stream_data,
     std::string const& file_prefix,
@@ -818,7 +820,9 @@ QPDF::writeJSON(
     }
     JSON::writeDictionaryClose(p, first_object, 2);
     JSON::writeDictionaryClose(p, first_qpdf, 1);
-    JSON::writeDictionaryClose(p, first, 0);
-    *p << "\n";
-    p->finish();
+    if (complete) {
+        JSON::writeDictionaryClose(p, first, 0);
+        *p << "\n";
+        p->finish();
+    }
 }
diff --git a/libqpdf/qpdf/auto_job_help.hh b/libqpdf/qpdf/auto_job_help.hh
index 5146ddae..6ade99f5 100644
--- a/libqpdf/qpdf/auto_job_help.hh
+++ b/libqpdf/qpdf/auto_job_help.hh
@@ -821,16 +821,18 @@ objects will be shown.
 )");
 ap.addOptionHelp("--json-stream-data", "json", "how to handle streams in json output", R"(--json-stream-data={none|inline|file}
 
-When used with --json-output, this option controls whether
-streams in json output should be omitted, written inline
-(base64-encoded) or written to a file. If "file" is chosen, the
-file will be the name of the output file appended with -nnn where
-nnn is the object number. The prefix can be overridden with
---json-stream-prefix.
+When used with --json, this option controls whether streams in
+json output should be omitted, written inline (base64-encoded)
+or written to a file. If "file" is chosen, the file will be the
+name of the output file appended with -nnn where nnn is the
+object number. The prefix can be overridden with
+--json-stream-prefix. The default is "none", except
+when --json-output is specified, in which case the default is
+"inline".
 )");
 ap.addOptionHelp("--json-stream-prefix", "json", "prefix for json stream data files", R"(--json-stream-prefix=file-prefix
 
-When used with --json-output, --json-stream-data=file-prefix
+When used with --json-stream-data=file, --json-stream-data=file-prefix
 sets the prefix for stream data files, overriding the default,
 which is to use the output file name. Whatever is given here
 will be appended with -nnn to create the name of the file that