[pager] use source line counts

Author: tstack

src/base/math_util.hh

@@ -162,4 +162,22 @@ count_digits(T n)
     return n == 0 ? 1 : 1 + std::floor(std::log10(std::abs(n)));
 }
 
+namespace lnav::math {
+
+template<typename T>
+T
+vmax(T a, T b)
+{
+    return (a > b) ? a : b;
+}
+
+template<typename T, typename... Args>
+T
+vmax(T a, T b, Args... args)
+{
+    return vmax(vmax(a, b), args...);
+}
+
+}  // namespace lnav::math
+
 #endif

src/lnav.cc

@@ -4172,10 +4172,12 @@ SELECT tbl_name FROM sqlite_master WHERE sql LIKE 'CREATE VIRTUAL TABLE%'
                 {
                     log_info("  input fully consumed");
                     rebuild_indexes_repeatedly();
-                    if (lnav_data.ld_active_files.fc_files.empty()
-                        || lnav_data.ld_active_files.fc_files[0]->size()
-                            < term_size.ws_row - 3)
-                    {
+
+                    auto max_height = lnav::math::vmax(
+                        lnav_data.ld_log_source.text_line_count(),
+                        lnav_data.ld_text_source.text_line_count());
+
+                    if (max_height < term_size.ws_row - 3) {
                         log_info("  input is smaller than screen, not paging");
                         lnav_data.ld_flags.set<lnav_flags::headless>();
                         verbosity = verbosity_t::standard;