# HG changeset patch
# User David Steele <dsteele#gmail.com>
# Date 1437180834 14400
#      Fri Jul 17 20:53:54 2015 -0400
# Node ID 041946b60bef09f73182c4d8fa2e3314bc84750b
# Parent  b2a1fe8f1b11d95b329d92f2011ac894b4098386
Issue 24241: Promote webbrowser preferred browser

diff -r b2a1fe8f1b11 -r 041946b60bef Doc/library/webbrowser.rst
--- a/Doc/library/webbrowser.rst	Fri Jul 17 11:59:57 2015 -0700
+++ b/Doc/library/webbrowser.rst	Fri Jul 17 20:53:54 2015 -0400
@@ -94,9 +94,9 @@
    variable or call :func:`get` with a nonempty argument matching the name of a
    handler you declare.
 
-A number of browser types are predefined.  This table gives the type names that
-may be passed to the :func:`get` function and the corresponding instantiations
-for the controller classes, all defined in this module.
+A number of browser types are predefined.  This table gives some of the type
+names that may be passed to the :func:`get` function and the corresponding
+instantiations for the controller classes, all defined in this module.
 
 +------------------------+-----------------------------------------+-------+
 | Type Name              | Class Name                              | Notes |
diff -r b2a1fe8f1b11 -r 041946b60bef Lib/webbrowser.py
--- a/Lib/webbrowser.py	Fri Jul 17 11:59:57 2015 -0700
+++ b/Lib/webbrowser.py	Fri Jul 17 20:53:54 2015 -0400
@@ -470,6 +470,22 @@
     if shutil.which("grail"):
         register("grail", Grail, None)
 
+def reorder(blist):
+    """Move the preferred browser to the top of the list"""
+
+    try:
+        # freedesktop environments
+        cmd = "xdg-mime query default text/html"
+        bpath = subprocess.check_output(cmd.split()).decode()
+
+        keyfn = lambda x: (bpath.find(x[1])<0 , x)
+        pref_order = sorted(enumerate(blist), key=keyfn)
+        blist = [x[1] for x in pref_order]
+    except OSError:
+        pass
+
+    return blist
+
 # Prefer X browsers if present
 if os.environ.get("DISPLAY"):
     register_X_browsers()
@@ -704,6 +720,10 @@
     register("firefox", None, MacOSXOSAScript('firefox'), -1)
     register("MacOSX", None, MacOSXOSAScript('default'), -1)
 
+# Attempt to identify the user's preferred broswer for this environment,
+# and move it to the top of th list
+_tryorder = reorder(_tryorder)
+
 
 # OK, now that we know what the default preference orders for each
 # platform are, allow user to override them with the BROWSER variable.