fixed #13627 - bail out on nested GUI projects instead of ignoring them silently

Author: firewave

cli/cmdlineparser.cpp

@@ -1165,6 +1165,10 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
                         // read underlying project
                         projectFile = projectFileGui;
                         projType = project.import(projectFileGui, &mSettings);
+                        if (projType == ImportProject::Type::CPPCHECK_GUI) {
+                            mLogger.printError("nested Cppcheck GUI projects are not supported.");
+                            return Result::Fail;
+                        }
                     }
                 }
                 if (projType == ImportProject::Type::VS_SLN || projType == ImportProject::Type::VS_VCXPROJ) {

test/cli/more-projects_test.py

@@ -893,7 +893,7 @@ def test_project_file_nested(tmp_path):
 
     args = ['--project={}'.format(level1_file)]
     out_lines = [
-        'cppcheck: error: no C or C++ source files found.'
+        'cppcheck: error: nested Cppcheck GUI projects are not supported.'
     ]
 
     assert_cppcheck(args, ec_exp=1, err_exp=[], out_exp=out_lines)