Write the estimated printing time comment after the config block, not before (#15897)

Co-authored-by: Fernando Marino <f.marino@rheagroup.com>
Co-authored-by: yw4z <ywsyildiz@gmail.com>

src/libslic3r/GCode.cpp

@@ -4174,6 +4174,28 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
 
     print.throw_if_canceled();
 
+    // Some firmwares only scan the last N lines for the time estimate, so the stats are written
+    // after the config block.
+    if (!is_bbl_printers && !skip_config_block) {
+        file.write("; CONFIG_BLOCK_START\n");
+        std::string full_config;
+        append_full_config(print, full_config);
+        if (!full_config.empty())
+          file.write(full_config);
+
+        // SoftFever: write compatiple info
+        int first_layer_bed_temperature = get_bed_temperature(0, true, print.config().curr_bed_type);
+        file.write_format("; first_layer_bed_temperature = %d\n", first_layer_bed_temperature);
+        file.write_format("; bed_shape = %s\n", print.full_print_config().opt_serialize("printable_area").c_str());
+        file.write_format("; first_layer_temperature = %d\n", print.config().nozzle_temperature_initial_layer.get_at(0));
+        file.write_format("; first_layer_height = %.3f\n", print.config().initial_layer_print_height.value);
+
+          //SF TODO
+//        file.write_format("; variable_layer_height = %d\n", print.ad.adaptive_layer_height ? 1 : 0);
+
+        file.write("; CONFIG_BLOCK_END\n\n");
+    }
+
     // Get filament stats.
     file.write(DoExport::update_print_stats_and_format_filament_stats(
     	// Const inputs
@@ -4200,26 +4222,6 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
                 GCodeProcessor::ETags::Estimated_Printing_Time_Placeholder)
             .c_str());
       file.write("\n");
-      if (!skip_config_block) {
-          file.write("; CONFIG_BLOCK_START\n");
-          std::string full_config;
-          append_full_config(print, full_config);
-          if (!full_config.empty())
-            file.write(full_config);
-
-          // SoftFever: write compatiple info
-          int first_layer_bed_temperature = get_bed_temperature(0, true, print.config().curr_bed_type);
-          file.write_format("; first_layer_bed_temperature = %d\n", first_layer_bed_temperature);
-          file.write_format("; bed_shape = %s\n", print.full_print_config().opt_serialize("printable_area").c_str());
-          file.write_format("; first_layer_temperature = %d\n", print.config().nozzle_temperature_initial_layer.get_at(0));
-          file.write_format("; first_layer_height = %.3f\n", print.config().initial_layer_print_height.value);
-
-            //SF TODO
-//          file.write_format("; variable_layer_height = %d\n", print.ad.adaptive_layer_height ? 1 : 0);
-
-          file.write("; CONFIG_BLOCK_END\n\n");
-      } // !skip_config_block
-
     }
     file.write("\n");
 

tests/fff_print/test_print.cpp

@@ -489,6 +489,25 @@ TEST_CASE("gcode_skip_config_block omits the resolved-settings comment block", "
     CHECK(gcode.find("; EXECUTABLE_BLOCK_START") != std::string::npos);
 }
 
+// Some firmwares only scan the last N lines of the file for "estimated printing time", so it
+// must stay close to EOF regardless of the resolved-settings config block's size.
+TEST_CASE("The estimated printing time comment stays near the end of the file", "[Print]")
+{
+    const std::string gcode = slice({ cube(20) }, {});
+    const size_t config_block_end = gcode.find("; CONFIG_BLOCK_END");
+    const size_t filament_stats   = gcode.find("; filament used [mm]");
+    const size_t time_comment     = gcode.find("estimated printing time");
+    REQUIRE(config_block_end != std::string::npos);
+    REQUIRE(filament_stats != std::string::npos);
+    REQUIRE(time_comment != std::string::npos);
+    CHECK(filament_stats > config_block_end);
+    CHECK(time_comment > filament_stats);
+
+    const size_t line_start = gcode.rfind('\n', time_comment) + 1;
+    const size_t trailing_lines = std::count(gcode.begin() + line_start, gcode.end(), '\n');
+    CHECK(trailing_lines <= 5);
+}
+
 // Custom G-code templates substitute placeholders during export.
 TEST_CASE("Custom G-code placeholders are substituted", "[Print]")
 {