Initialize bisect state when opening document

Otherwise, when opening a document at page 1, and no jumps are added,
bisect does not understand it has to initialize the bisect range, and
does not move from page 1.
Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

shortcuts.c

@@ -722,7 +722,11 @@ sc_jumplist(girara_session_t* session, girara_argument_t* argument,
   zathura_t* zathura = session->global.data;
   g_return_val_if_fail(argument != NULL, false);
   g_return_val_if_fail(zathura->document != NULL, false);
-  g_return_val_if_fail(zathura->jumplist.size != 0, false);
+
+  /* if no jumps in the jumplist */
+  if (zathura->jumplist.size == 0) {
+    return;
+  }
 
   GtkAdjustment* hadj = gtk_scrolled_window_get_hadjustment(GTK_SCROLLED_WINDOW(session->gtk.view));
   GtkAdjustment* vadj = gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(session->gtk.view));

zathura.c

@@ -654,6 +654,11 @@ document_open(zathura_t* zathura, const char* path, const char* password,
     zathura_document_set_adjust_mode(document, ZATHURA_ADJUST_NONE);
   }
 
+  /* initialize bisect state */
+  zathura->bisect.start = 0;
+  zathura->bisect.last_jump = zathura_document_get_current_page_number(document);
+  zathura->bisect.end = number_of_pages - 1;
+
   /* update statusbar */
   bool basename_only = false;
   girara_setting_get(zathura->ui.session, "statusbar-basename", &basename_only);