Use npos instead of -1

src/control/LatexController.cpp

@@ -71,8 +71,8 @@ auto LatexController::findTexDependencies() -> LatexController::FindDependencySt
  */
 void LatexController::findSelectedTexElement() {
     this->doc->lock();
-    int pageNr = this->control->getCurrentPageNo();
-    if (pageNr == -1) {
+    auto pageNr = this->control->getCurrentPageNo();
+    if (pageNr == npos) {
         this->doc->unlock();
         return;
     }

src/control/ScrollHandler.cpp

@@ -41,7 +41,7 @@ void ScrollHandler::scrollToPage(const PageRef& page, double top) {
     auto p = doc->indexOf(page);
     doc->unlock();
 
-    if (p != -1) {
+    if (p != npos) {
         scrollToPage(p, top);
     }
 }

src/gui/PageView.cpp

@@ -128,9 +128,9 @@ auto XojPageView::searchTextOnPage(string& text, int* occures, double* top) -> b
             return true;
         }
 
-        int pNr = this->page->getPdfPageNr();
+        auto pNr = this->page->getPdfPageNr();
         XojPdfPageSPtr pdf = nullptr;
-        if (pNr != -1) {
+        if (pNr != npos) {
             Document* doc = xournal->getControl()->getDocument();
 
             doc->lock();

src/gui/dialog/backgroundSelect/PdfPagesDialog.cpp

@@ -24,7 +24,7 @@ PdfPagesDialog::PdfPagesDialog(GladeSearchpath* gladeSearchPath, Document* doc,
 
         if (p->getBackgroundType().isPdfPage()) {
             auto pdfPage = p->getPdfPageNr();
-            if (pdfPage >= 0 && pdfPage < static_cast<int>(elements.size())) {
+            if (pdfPage >= 0 && pdfPage < elements.size()) {
                 (dynamic_cast<PdfElementView*>(elements[p->getPdfPageNr()]))->setUsed(true);
             }
         }

src/model/Document.cpp

@@ -258,7 +258,7 @@ auto Document::fillPageLabels(GtkTreeModel* treeModel, GtkTreePath* path, GtkTre
     auto page = doc->findPdfPage(link->dest->getPdfPage());
 
     gchar* pageLabel = nullptr;
-    if (page != -1) {
+    if (page != npos) {
         pageLabel = g_strdup_printf("%lu", page + 1);
     }
     gtk_tree_store_set(GTK_TREE_STORE(treeModel), iter, DOCUMENT_LINKS_COLUMN_PAGE_NUMBER, pageLabel, -1);

src/undo/InsertDeletePageUndoAction.cpp

@@ -70,7 +70,7 @@ auto InsertDeletePageUndoAction::deletePage(Control* control) -> bool {
     // It's not great practise but it works.
     // doc->lock();
     auto pNr = doc->indexOf(page);
-    if (pNr == -1) {
+    if (pNr == npos) {
         //	doc->unlock();
         // this should not happen
         return false;

src/undo/PageBackgroundChangedUndoAction.cpp

@@ -31,7 +31,7 @@ auto PageBackgroundChangedUndoAction::undo(Control* control) -> bool {
 
     Document* doc = control->getDocument();
     auto pageNr = doc->indexOf(this->page);
-    if (pageNr == -1) {
+    if (pageNr == npos) {
         return false;
     }
 
@@ -57,7 +57,7 @@ auto PageBackgroundChangedUndoAction::redo(Control* control) -> bool {
 
     auto pageNr = doc->indexOf(this->page);
 
-    if (pageNr == -1) {
+    if (pageNr == npos) {
         return false;
     }