Usability: Fixed loading of platform file placed in same path as project file

cli/cmdlineparser.cpp

@@ -624,7 +624,7 @@ bool CmdLineParser::parseFromArgs(int argc, const char* const argv[])
                         mSettings->platform(Settings::Native);
                     else if (platform == "unspecified" || platform == "Unspecified" || platform == "")
                         ;
-                    else if (!mSettings->loadPlatformFile(argv[0], platform)) {
+                    else if (!mSettings->loadPlatformFile(projectFile.c_str(), platform) && !mSettings->loadPlatformFile(argv[0], platform)) {
                         std::string message("cppcheck: error: unrecognized platform: \"");
                         message += platform;
                         message += "\".";

lib/platform.cpp

@@ -162,6 +162,8 @@ bool cppcheck::Platform::loadPlatformFile(const char exename[], const std::strin
         std::vector<std::string> filenames;
         filenames.push_back(filename + ".xml");
         if (exename && (std::string::npos != Path::fromNativeSeparators(exename).find('/'))) {
+            filenames.push_back(Path::getPathFromFilename(Path::fromNativeSeparators(exename)) + filename);
+            filenames.push_back(Path::getPathFromFilename(Path::fromNativeSeparators(exename)) + filename);
             filenames.push_back(Path::getPathFromFilename(Path::fromNativeSeparators(exename)) + "platforms/" + filename);
             filenames.push_back(Path::getPathFromFilename(Path::fromNativeSeparators(exename)) + "platforms/" + filename + ".xml");
         }

test/cli/test-more-projects.py

@@ -32,3 +32,32 @@ def test_project_force_U():
         ret, stdout, stderr = cppcheck(['--project=' + compile_commands, '--force', '-UMACRO1', '-rp=' + temp_folder, '--template=cppcheck1'])
         assert stderr == '[bug1.cpp:2]: (error) Division by zero.\n'
 
+
+def test_project_custom_platform():
+    """
+    import cppcheck project that contains a custom platform file
+    """
+    with tempfile.TemporaryDirectory('10018') as temp_folder:
+        project_file = os.path.join(temp_folder, 'Project.cppcheck')
+
+        with open(project_file, 'wt') as f:
+            f.write("""
+                    <?xml version="1.0" encoding="UTF-8"?>
+                    <project version="1">
+                      <platform>p1.xml</platform>
+                      <paths>
+                        <dir name="."/>
+                      </paths>
+                    </project>
+                    """)
+
+        with open(os.path.join(temp_folder, 'p1.xml'), 'wt') as f:
+            f.write('<?xml version="1.0"?>\n<platform/>')
+
+        with open(os.path.join(temp_folder, '1.c'), 'wt') as f:
+            f.write("int x;")
+
+        ret, stdout, stderr = cppcheck(['--project=' + project_file, '--template=cppcheck1'])
+        assert stderr == ''
+
+