add errors file

man/man4/acme.4

diff --git a/man/man4/acme.4 b/man/man4/acme.4
index 40143a4..1312904 100644
--- a/man/man4/acme.4
+++ b/man/man4/acme.4
@@ -280,6 +280,17 @@
 and sets the address to the null string at the end of the returned
 characters.
 .TP
+.B errors
+Writing to the
+.B errors
+file appends to the body of the
+.IB dir /+Errors
+window, where
+.I dir
+is the directory currently named in the tag.
+The window is created if necessary,
+but not until text is actually written.
+.TP
 .B event
 When a window's
 .B event
@@ -395,6 +406,13 @@
 Text written to
 .B tag
 is always appended; the file offset is ignored.
+.TP
+.B xdata
+The
+.B xdata
+file like
+.B data
+except that reads stop at the end address.
 .SH SOURCE
 .B \*9/src/cmd/acme
 .SH SEE ALSO

src/cmd/acme/dat.h

diff --git a/src/cmd/acme/dat.h b/src/cmd/acme/dat.h
index 4ac0d67..19229e7 100644
--- a/src/cmd/acme/dat.h
+++ b/src/cmd/acme/dat.h
@@ -15,6 +15,7 @@
 	QWctl,
 	QWdata,
 	QWeditout,
+	QWerrors,
 	QWevent,
 	QWrdsel,
 	QWwrsel,

src/cmd/acme/fns.h

diff --git a/src/cmd/acme/fns.h b/src/cmd/acme/fns.h
index c61f96e..74a381e 100644
--- a/src/cmd/acme/fns.h
+++ b/src/cmd/acme/fns.h
@@ -28,6 +28,7 @@
 uint loadfile(int, uint, int*, int(*)(void*, uint, Rune*, int), void*);
 
 Window*	errorwin(Mntdir*, int);
+Window*	errorwinforwin(Window*);
 Runestr cleanrname(Runestr);
 void	run(Window*, char*, Rune*, int, int, char*, char*, int);
 void fsysclose(void);

src/cmd/acme/fsys.c

diff --git a/src/cmd/acme/fsys.c b/src/cmd/acme/fsys.c
index 536a333..3123608 100644
--- a/src/cmd/acme/fsys.c
+++ b/src/cmd/acme/fsys.c
@@ -83,6 +83,7 @@
 	{ "ctl",		QTFILE,		QWctl,		0600 },
 	{ "data",		QTFILE,		QWdata,		0600 },
 	{ "editout",	QTFILE,		QWeditout,	0200 },
+	{ "errors",		QTFILE,		QWerrors,		0200 },
 	{ "event",		QTFILE,		QWevent,		0600 },
 	{ "rdsel",		QTFILE,		QWrdsel,		0400 },
 	{ "wrsel",		QTFILE,		QWwrsel,		0200 },

src/cmd/acme/util.c

diff --git a/src/cmd/acme/util.c b/src/cmd/acme/util.c
index f9387df..c224cce 100644
--- a/src/cmd/acme/util.c
+++ b/src/cmd/acme/util.c
@@ -129,6 +129,49 @@
 	return w;
 }
 
+/*
+ * Incoming window should be locked. 
+ * It will be unlocked and returned window
+ * will be locked in its place.
+ */
+Window*
+errorwinforwin(Window *w)
+{
+	int i, n, nincl, owner;
+	Rune **incl;
+	Runestr dir;
+	Text *t;
+
+	t = &w->body;
+	dir = dirname(t, nil, 0);
+	if(dir.nr==1 && dir.r[0]=='.'){	/* sigh */
+		free(dir.r);
+		dir.r = nil;
+		dir.nr = 0;
+	}
+	incl = nil;
+	nincl = w->nincl;
+	if(nincl > 0){
+		incl = emalloc(nincl*sizeof(Rune*));
+		for(i=0; i<nincl; i++){
+			n = runestrlen(w->incl[i]);
+			incl[i] = runemalloc(n+1);
+			runemove(incl[i], w->incl[i], n);
+		}
+	}
+	owner = w->owner;
+	winunlock(w);
+	for(;;){
+		w = errorwin1(dir.r, dir.nr, incl, nincl);
+		winlock(w, owner);
+		if(w->col != nil)
+			break;
+		/* window deleted too fast */
+		winunlock(w);
+	}
+	return w;
+}
+
 typedef struct Warning Warning;
 
 struct Warning{

src/cmd/acme/xfid.c

diff --git a/src/cmd/acme/xfid.c b/src/cmd/acme/xfid.c
index 579f194..126a5fe 100644
--- a/src/cmd/acme/xfid.c
+++ b/src/cmd/acme/xfid.c
@@ -444,6 +444,11 @@
 		respond(x, &fc, nil);
 		break;
 
+	case QWerrors:
+		w = errorwinforwin(w);
+		t = &w->body;
+		goto BodyTag;
+
 	case QWbody:
 	case QWwrsel:
 		t = &w->body;