Fix running emrun tests on Linux against the Linux system browser. Fix emrun to work around Firefox https://bugzil.la/1996614

Author: juj

emrun.py

@@ -1768,7 +1768,7 @@ def run(args):  # noqa: C901, PLR0912, PLR0915
       if browser_exe == 'cmd':
         url = url.replace('&', '^&')
       url = url.replace('0.0.0.0', 'localhost')
-      browser += browser_args + [url]
+      browser += browser_args
 
   if options.kill_start:
     pname = processname_killed_atexit
@@ -1801,6 +1801,13 @@ def run(cmd):
 
     browser += ['-no-remote', '--profile', profile_dir.replace('\\', '/')]
 
+  # Pass the URL to open as the very last item on the command line, and use the -url xxx parameter
+  # to open the url to work around https://bugzil.la/1996614.
+  if 'firefox' in browser_exe:
+    browser += ['-url', url]
+  else:
+    browser += [url]
+
   if options.system_info:
     logi('Time of run: ' + time.strftime("%x %X"))
     logi(get_system_info(format_json=options.json))

test/browser_common.py

@@ -37,7 +37,7 @@
 from tools import feature_matrix, utils
 from tools.feature_matrix import UNSUPPORTED
 from tools.shared import DEBUG, EMCC, exit_with_error
-from tools.utils import MACOS, WINDOWS, memoize, path_from_root, read_binary
+from tools.utils import LINUX, MACOS, WINDOWS, memoize, path_from_root, read_binary
 
 logger = logging.getLogger('common')
 
@@ -167,6 +167,13 @@ def get_firefox_version():
     return UNSUPPORTED
   exe_path = shlex.split(EMTEST_BROWSER)[0]
   ini_path = os.path.join(os.path.dirname(exe_path), '../Resources/platform.ini' if MACOS else 'platform.ini')
+  # On Linux, Firefox system installation uses a specific directory structure.
+  if LINUX and exe_path.startswith('/usr/bin/'):
+    if os.path.isfile('/usr/lib/firefox-esr/platform.ini'):
+      ini_path = '/usr/lib/firefox-esr/platform.ini'
+    elif os.path.isfile('/usr/lib/firefox/platform.ini'):
+      ini_path = '/usr/lib/firefox/platform.ini'
+
   # Extract the first numeric part before any dot (e.g. "Milestone=102.15.1" → 102)
   m = re.search(r"^Milestone=(.*)$", read_file(ini_path), re.MULTILINE)
   milestone = m.group(1).strip()
@@ -318,7 +325,17 @@ def configure_test_browser():
     return
 
   if not EMTEST_BROWSER:
-    EMTEST_BROWSER = 'google-chrome'
+    def find_in_path(cmd):
+      for path in os.environ['PATH'].split(os.pathsep):
+        exe_file = os.path.join(path, cmd)
+        if WINDOWS:
+          exe_file += '.exe'
+        if os.path.isfile(exe_file):
+          return exe_file
+
+    EMTEST_BROWSER = find_in_path('google-chrome')
+    if not EMTEST_BROWSER:
+      EMTEST_BROWSER = find_in_path('firefox')
 
   if WINDOWS and '"' not in EMTEST_BROWSER and "'" not in EMTEST_BROWSER:
     # On Windows env. vars canonically use backslashes as directory delimiters, e.g.