fix(page_layout): apply margins to current page in Apply To selection

Apply Margins used to skip m_pageId even when the dialog included the
current page (e.g. "This page and the following every other page"), so
alternating margin workflows did not persist settings for the active page.

Add PageSequence unit tests for the 75-page every-other pattern from #144.

Author: pablogventura

src/core/filters/page_layout/OptionsWidget.cpp

@@ -319,10 +319,6 @@ void OptionsWidget::applyMargins(const std::set<PageId>& pages,
 
   const bool autoMarginsEnabled = m_settings->isPageAutoMarginsEnabled(m_pageId);
   for (const PageId& pageId : pages) {
-    if (pageId == m_pageId) {
-      continue;
-    }
-
     m_settings->setPageAutoMarginsEnabled(pageId, autoMarginsEnabled);
     if (autoMarginsEnabled) {
       m_settings->invalidateContentSize(pageId);

src/core/tests/CMakeLists.txt

@@ -7,6 +7,7 @@ set(sources
     TestMargins.cpp
     TestPageId.cpp
     TestPageRange.cpp
+    TestPageSequence.cpp
     TestSelectContentApply.cpp
     TestSmartFilenameOrdering.cpp
     TestUnits.cpp)

src/core/tests/TestPageSequence.cpp

@@ -0,0 +1,83 @@
+// Copyright (C) 2019  Joseph Artsimovich <joseph.artsimovich@gmail.com>, 4lex4 <4lex49@zoho.com>
+// Use of this source code is governed by the GNU GPLv3 license that can be found in the LICENSE file.
+
+#include <ImageId.h>
+#include <PageId.h>
+#include <PageInfo.h>
+#include <PageSequence.h>
+
+#include <boost/test/unit_test.hpp>
+#include <set>
+#include <vector>
+
+namespace Tests {
+
+static PageInfo makePage(const char* path, const int imageIdx) {
+  PageInfo info;
+  info.setId(PageId(ImageId(path, imageIdx), PageId::SINGLE_PAGE));
+  return info;
+}
+
+BOOST_AUTO_TEST_SUITE(PageSequenceTestSuite)
+
+BOOST_AUTO_TEST_CASE(select_this_page_and_following_every_other_from_first) {
+  PageSequence seq;
+  std::vector<PageInfo> pages;
+  for (int i = 0; i < 75; ++i) {
+    pages.push_back(makePage("/scan", i));
+    seq.append(pages.back());
+  }
+
+  const PageId base = pages[0].id();
+  const std::set<PageId> result = seq.selectThisPageAndFollowingEveryOther(base);
+
+  BOOST_CHECK_EQUAL(result.size(), 38u);
+  for (int i = 0; i < 75; i += 2) {
+    BOOST_CHECK(result.count(pages[static_cast<size_t>(i)].id()) == 1);
+  }
+  for (int i = 1; i < 75; i += 2) {
+    BOOST_CHECK(result.count(pages[static_cast<size_t>(i)].id()) == 0);
+  }
+}
+
+BOOST_AUTO_TEST_CASE(select_this_page_and_following_every_other_from_second) {
+  PageSequence seq;
+  std::vector<PageInfo> pages;
+  for (int i = 0; i < 75; ++i) {
+    pages.push_back(makePage("/scan", i));
+    seq.append(pages.back());
+  }
+
+  const PageId base = pages[1].id();
+  const std::set<PageId> result = seq.selectThisPageAndFollowingEveryOther(base);
+
+  BOOST_CHECK_EQUAL(result.size(), 37u);
+  for (int i = 1; i < 75; i += 2) {
+    BOOST_CHECK(result.count(pages[static_cast<size_t>(i)].id()) == 1);
+  }
+  for (int i = 0; i < 75; i += 2) {
+    BOOST_CHECK(result.count(pages[static_cast<size_t>(i)].id()) == 0);
+  }
+}
+
+BOOST_AUTO_TEST_CASE(select_this_page_and_following_every_other_partitions_75_pages) {
+  PageSequence seq;
+  std::vector<PageInfo> pages;
+  for (int i = 0; i < 75; ++i) {
+    pages.push_back(makePage("/scan", i));
+    seq.append(pages.back());
+  }
+
+  const std::set<PageId> oddFromFirst = seq.selectThisPageAndFollowingEveryOther(pages[0].id());
+  const std::set<PageId> evenFromSecond = seq.selectThisPageAndFollowingEveryOther(pages[1].id());
+
+  for (int i = 0; i < 75; ++i) {
+    const bool inOdd = oddFromFirst.count(pages[static_cast<size_t>(i)].id()) != 0;
+    const bool inEven = evenFromSecond.count(pages[static_cast<size_t>(i)].id()) != 0;
+    BOOST_CHECK(inOdd != inEven);
+  }
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}  // namespace Tests