From 2c6fe1805a2fa5fae719224dff44f41a823466b8 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Sat, 12 Aug 2017 12:08:23 -0400
Subject: Support groups of pages in --split-pages (fixes #30)

---
 qpdf/qpdf.cc                              |  33 +++++++++++++++++++++---------
 qpdf/qtest/qpdf.test                      |  16 +++++++++++++--
 qpdf/qtest/qpdf/split-exp-group-01-05.pdf | Bin 0 -> 2050 bytes
 qpdf/qtest/qpdf/split-exp-group-06-10.pdf | Bin 0 -> 2051 bytes
 qpdf/qtest/qpdf/split-exp-group-11-11.pdf | Bin 0 -> 756 bytes
 5 files changed, 37 insertions(+), 12 deletions(-)
 create mode 100644 qpdf/qtest/qpdf/split-exp-group-01-05.pdf
 create mode 100644 qpdf/qtest/qpdf/split-exp-group-06-10.pdf
 create mode 100644 qpdf/qtest/qpdf/split-exp-group-11-11.pdf

diff --git a/qpdf/qpdf.cc b/qpdf/qpdf.cc
index 54e1b652..f3051eb4 100644
--- a/qpdf/qpdf.cc
+++ b/qpdf/qpdf.cc
@@ -43,7 +43,7 @@ struct Options
         password(0),
         linearize(false),
         decrypt(false),
-        split_pages(false),
+        split_pages(0),
         copy_encryption(false),
         encryption_file(0),
         encryption_file_password(0),
@@ -98,7 +98,7 @@ struct Options
     char const* password;
     bool linearize;
     bool decrypt;
-    bool split_pages;
+    int split_pages;
     bool copy_encryption;
     char const* encryption_file;
     char const* encryption_file_password;
@@ -1338,7 +1338,8 @@ static void parse_options(int argc, char* argv[], Options& o)
             }
             else if (strcmp(arg, "split-pages") == 0)
             {
-                o.split_pages = true; // XXX
+                int n = ((parameter == 0) ? 1 : atoi(parameter));
+                o.split_pages = n;
             }
             else if (strcmp(arg, "deterministic-id") == 0)
             {
@@ -2007,16 +2008,28 @@ static void write_outfile(QPDF& pdf, Options& o)
 
         std::vector<QPDFObjectHandle> const& pages = pdf.getAllPages();
         int pageno_len = QUtil::int_to_string(pages.size()).length();
-        int pageno = 0;
-        for (std::vector<QPDFObjectHandle>::const_iterator iter = pages.begin();
-             iter != pages.end(); ++iter)
+        unsigned int num_pages = pages.size();
+        for (unsigned int i = 0; i < num_pages; i += o.split_pages)
         {
-            QPDFObjectHandle page = *iter;
-            std::string outfile =
-                before + QUtil::int_to_string(++pageno, pageno_len) + after;
+            unsigned int first = i + 1;
+            unsigned int last = i + o.split_pages;
+            if (last > num_pages)
+            {
+                last = num_pages;
+            }
             QPDF outpdf;
             outpdf.emptyPDF();
-            outpdf.addPage(page, false);
+            for (unsigned int pageno = first; pageno <= last; ++pageno)
+            {
+                QPDFObjectHandle page = pages.at(pageno - 1);
+                outpdf.addPage(page, false);
+            }
+            std::string page_range = QUtil::int_to_string(first, pageno_len);
+            if (o.split_pages > 1)
+            {
+                page_range += "-" + QUtil::int_to_string(last, pageno_len);
+            }
+            std::string outfile = before + page_range + after;
             QPDFWriter w(outpdf, outfile.c_str());
             set_writer_options(outpdf, o, w);
             w.write();
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index c86e290f..e5a97058 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -713,7 +713,7 @@ foreach my $d (
 }
 show_ntests();
 # ----------
-$td->notify("--- Split Pages ---"); # XXXX
+$td->notify("--- Split Pages ---");
 # sp = split-pages
 my @sp_cases = (
     [11, '%d at beginning', '', '%d_split-out.zdf'],
@@ -722,12 +722,24 @@ my @sp_cases = (
     [11, 'pdf extension', '', 'split-out.Pdf'],
     [4, 'fallback', '--pages 11-pages.pdf 1-3 minimal.pdf --', 'split-out'],
     );
-$n_tests += 1;
+$n_tests += 5;
 for (@sp_cases)
 {
     $n_tests += 1 + $_->[0];
 }
 
+$td->runtest("split page group > 1",
+             {$td->COMMAND => "qpdf --static-id --split-pages=5 11-pages.pdf" .
+                  " split-out-group.pdf"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+foreach my $f ('01-05', '06-10', '11-11')
+{
+    $td->runtest("checkout group $f",
+                 {$td->FILE => "split-out-group-$f.pdf"},
+                 {$td->FILE => "split-exp-group-$f.pdf"});
+}
+
 $td->runtest("no split-pages to stdout",
              {$td->COMMAND => "qpdf --split-pages 11-pages.pdf -"},
              {$td->FILE => "split-pages-stdout.out", $td->EXIT_STATUS => 2},
diff --git a/qpdf/qtest/qpdf/split-exp-group-01-05.pdf b/qpdf/qtest/qpdf/split-exp-group-01-05.pdf
new file mode 100644
index 00000000..318b3814
Binary files /dev/null and b/qpdf/qtest/qpdf/split-exp-group-01-05.pdf differ
diff --git a/qpdf/qtest/qpdf/split-exp-group-06-10.pdf b/qpdf/qtest/qpdf/split-exp-group-06-10.pdf
new file mode 100644
index 00000000..7f8b652f
Binary files /dev/null and b/qpdf/qtest/qpdf/split-exp-group-06-10.pdf differ
diff --git a/qpdf/qtest/qpdf/split-exp-group-11-11.pdf b/qpdf/qtest/qpdf/split-exp-group-11-11.pdf
new file mode 100644
index 00000000..158f9c78
Binary files /dev/null and b/qpdf/qtest/qpdf/split-exp-group-11-11.pdf differ
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