pager: improve support for various flavors of `more` on Windows
authorMatt Harbison <matt_harbison@yahoo.com>
Fri, 24 Mar 2017 22:40:08 -0400
changeset 31624 c60091fa1426
parent 31623 a01e1132f6fa
child 31625 c208bc65318a
pager: improve support for various flavors of `more` on Windows Hardcoding 'more' -> 'more.com' means that 'more.exe' from MSYS would need to be configured with its *.exe extension. This will resolve to either one, as cmd.exe would have done if the command ran through the shell. Something that's maybe problematic with this is it comes after 'pageractive' and various ui configs have been set by the calling method. But the other early exits in this method don't undo those changes either.
mercurial/ui.py
--- a/mercurial/ui.py	Fri Mar 24 15:05:42 2017 -0700
+++ b/mercurial/ui.py	Fri Mar 24 22:40:08 2017 -0400
@@ -846,15 +846,6 @@
         if not pagercmd:
             return
 
-        if pycompat.osname == 'nt':
-            # `more` cannot be invoked with shell=False, but `more.com` can.
-            # Hide this implementation detail from the user, so we can also get
-            # sane bad PAGER behavior.  If args are also given, the space in the
-            # command line forces shell=True, so that case doesn't need to be
-            # handled here.
-            if pagercmd == 'more':
-                pagercmd = 'more.com'
-
         self.debug('starting pager for command %r\n' % command)
         self.flush()
         self.pageractive = True
@@ -881,6 +872,21 @@
         # simple pager command configurations, we can degrade
         # gracefully and tell the user about their broken pager.
         shell = any(c in command for c in "|&;<>()$`\\\"' \t\n*?[#~=%")
+
+        if pycompat.osname == 'nt' and not shell:
+            # Window's built-in `more` cannot be invoked with shell=False, but
+            # its `more.com` can.  Hide this implementation detail from the
+            # user so we can also get sane bad PAGER behavior.  MSYS has
+            # `more.exe`, so do a cmd.exe style resolution of the executable to
+            # determine which one to use.
+            fullcmd = util.findexe(command)
+            if not fullcmd:
+                self.warn(_("missing pager command '%s', skipping pager\n")
+                          % command)
+                return
+
+            command = fullcmd
+
         try:
             pager = subprocess.Popen(
                 command, shell=shell, bufsize=-1,