Fix #13645 (fail to load platform when executing Cppcheck in PATH)

Author: danmar

cli/cmdlineparser.cpp

@@ -421,7 +421,7 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
 
     std::vector<std::string> lookupPaths{
         Path::getCurrentPath(), // TODO: do we want to look in CWD?
-        Path::getPathFromFilename(argv[0])
+        Path::getPathFromFilename(mSettings.exename),
     };
 
     bool executorAuto = true;

test/cli/lookup_test.py

@@ -381,6 +381,27 @@ def test_platform_lookup_ext(tmpdir):
     ]
 
 
+def test_platform_lookup_path(tmpdir):
+    test_file = os.path.join(tmpdir, 'test.c')
+    with open(test_file, 'wt'):
+        pass
+
+    c = 'cppcheck.exe' if sys.platform == 'win32' else 'cppcheck'
+    path = os.path.dirname(__lookup_cppcheck_exe())
+    env = os.environ.copy()
+    env['PATH'] = path
+    exitcode, stdout, stderr, exe = cppcheck_ex(args=['--debug-lookup=platform', '--platform=avr8.xml', test_file], cppcheck_exe=c, cwd=str(tmpdir), env=env)
+    assert exitcode == 0, stdout if stdout else stderr
+    lines = stdout.splitlines()
+    assert lines == [
+        "looking for platform 'avr8.xml'",
+        "try to load platform file '{}/avr8.xml' ... Error=XML_ERROR_FILE_NOT_FOUND ErrorID=3 (0x3) Line number=0: filename={}/avr8.xml".format(tmpdir, tmpdir),
+        "try to load platform file '{}/platforms/avr8.xml' ... Error=XML_ERROR_FILE_NOT_FOUND ErrorID=3 (0x3) Line number=0: filename={}/platforms/avr8.xml".format(tmpdir, tmpdir),
+        "try to load platform file '{}/avr8.xml' ... Error=XML_ERROR_FILE_NOT_FOUND ErrorID=3 (0x3) Line number=0: filename={}/avr8.xml".format(path, path),
+        "try to load platform file '{}/platforms/avr8.xml' ... Success".format(path),
+        'Checking {} ...'.format(test_file)
+    ]
+
 def test_platform_lookup_notfound(tmpdir):
     test_file = os.path.join(tmpdir, 'test.c')
     with open(test_file, 'wt'):