Do not set s nor p parameter to export URL if screen has no limit

Closes #12212

sao/src/window.js

@@ -2190,7 +2190,8 @@
             } else {
                 domain = this.screen.search_domain(
                     this.screen.screen_container.get_text());
-                if (!this.ignore_search_limit.prop('checked')) {
+                if (!this.ignore_search_limit.prop('checked') &&
+                    this.screen.limit !== null) {
                     query_string.push(['s', this.screen.limit.toString()]);
                     query_string.push(
                         ['p', Math.floor(

tryton/tryton/gui/window/win_export.py

@@ -470,7 +470,8 @@ class WinExport(WinCSV):
         else:
             domain = self.screen.search_domain(
                 self.screen.screen_container.get_text())
-            if not self.ignore_search_limit.get_active():
+            if (not self.ignore_search_limit.get_active()
+                    and self.screen.limit is not None):
                 query_string.append(('s', str(self.screen.limit)))
                 query_string.append(
                     ('p', str(self.screen.offset // self.screen.limit)))