Let mparse_readfd() use mparse_open() and mparse_wait()

and let mparse_open() fall back to .gz files
such that .so works even when the target is zipped,
requested by and in part using ideas from <bapt at FreeBSD>.
While here, make sure files are readable before forking,
both for efficiency and for better error reporting.

1 files changed, 18 insertions, 7 deletions

diff --git a/mandoc.3 b/mandoc.3
index 08a0d168..f05fdac9 100644
--- a/mandoc.3
+++ b/mandoc.3
@@ -1,4 +1,4 @@
-.\"	$Id: mandoc.3,v 1.28 2014/11/26 21:40:17 schwarze Exp $
+.\"	$Id: mandoc.3,v 1.29 2014/11/26 23:42:14 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
@@ -396,6 +396,12 @@ open with
 .Xr gunzip 1 ;
 otherwise, with
 .Xr open 2 .
+If
+.Xr open 2
+fails, append
+.Pa .gz
+and try with
+.Xr gunzip 1 .
 Return a file descriptor open for reading in
 .Fa fd ,
 or -1 on failure.
@@ -410,14 +416,18 @@ implemented in
 Parse a file or file descriptor.
 If
 .Va fd
-is -1,
+is -1, open
 .Va fname
-is opened for reading.
+with
+.Fn mparse_open .
 Otherwise,
 .Va fname
 is assumed to be the name associated with
 .Va fd .
-This may be called multiple times with different parameters; however,
+Calls
+.Fn mparse_wait
+before returning.
+This function may be called multiple times with different parameters; however,
 .Fn mparse_reset
 should be invoked between parses.
 Declared in
@@ -461,11 +471,12 @@ implemented in
 .It Fn mparse_wait
 Bury a
 .Xr gunzip 1
-child process
-.Fa child_pid
-that was spawned with
+child process that was spawned with
 .Fn mparse_open .
 To be called after the parse sequence is complete.
+Not needed after
+.Fn mparse_readfd ,
+but does no harm in that case, either.
 Returns
 .Dv MANDOCLEVEL_OK
 on success and