Add reader.errmsg().

README.rst

@@ -87,6 +87,17 @@ time the file was checked.
 
 XXX ...
 
+.. _xreader.errmsg():
+
+STRING xreader.errmsg()
+-----------------------
+
+Returns the error message for any error condition determined the last
+time the file was checked, or a message indicating that there was no
+error.
+
+XXX ...
+
 .. _file.version():
 
 STRING version()

src/tests/errors.vtc

@@ -2,7 +2,7 @@
 
 varnishtest "reader.error()"
 
-shell {echo -n "foo bar baz quux" > ${tmpdir}/error}
+shell {touch ${tmpdir}/error}
 
 varnish v1 -vcl {
 	import ${vmod_file};
@@ -18,6 +18,7 @@ varnish v1 -vcl {
 
 	sub vcl_synth {
 		set resp.http.Error = rdr.error();
+		set resp.http.Errmsg = rdr.errmsg();
 		return (deliver);
 	}
 } -start
@@ -27,14 +28,21 @@ client c1 {
 	rxresp
 	expect resp.status == 200
 	expect resp.http.Error == "false"
+	expect resp.http.Errmsg == "No error"
 } -run
 
 shell {rm -f ${tmpdir}/error}
 delay .1
 
-client c1 {
+client c2 {
 	txreq
 	rxresp
 	expect resp.status == 200
 	expect resp.http.Error == "true"
+	expect resp.http.Errmsg ~ "^vmod file failure: rdr: cannot read info about"
 } -run
+
+shell {touch ${tmpdir}/error}
+delay .1
+
+client c1 -run

src/vmod_file.c

@@ -514,6 +514,16 @@ vmod_reader_error(VRT_CTX, struct VPFX(file_reader) *rdr)
 	return (rdr->flags & RDR_ERROR);
 }
 
+VCL_STRING
+vmod_reader_errmsg(VRT_CTX, struct VPFX(file_reader) *rdr)
+{
+	CHECK_OBJ_NOTNULL(rdr, FILE_READER_MAGIC);
+	(void)ctx;
+
+	AN(rdr->errbuf);
+	return (rdr->errbuf);
+}
+
 VCL_STRING
 vmod_version(VRT_CTX)
 {

src/vmod_file.vcc

@@ -64,6 +64,14 @@ time the file was checked.
 
 XXX ...
 
+$Method STRING .errmsg()
+
+Returns the error message for any error condition determined the last
+time the file was checked, or a message indicating that there was no
+error.
+
+XXX ...
+
 $Function STRING version()
 
 Return the version string for this VMOD.