add the failed() method

src/tests/b01.vtc

@@ -15,6 +15,16 @@ varnish v1 -vcl+backend {
 	}
 
         sub vcl_recv {
+	    	if (foobar.failed()) {
+		   return(synth(999, "foobar failed"));
+		}
+	    	if (snafu.failed()) {
+		   return(synth(999, "snafu failed"));
+		}
+	    	if (bar.failed()) {
+		   return(synth(999, "bar failed"));
+		}
+
                 if (foobar.match(req.url)) {
                         return(pass);
                 } else if (snafu.match(req.url)) {

src/tests/b05.vtc

@@ -12,6 +12,12 @@ varnish v1 -vcl+backend {
 	        new paren = re.regex("(");
 	}
 
+	sub vcl_recv {
+	    	if (!paren.failed()) {
+		        return(synth(999, "paren should have failed"));
+		}
+	}
+
 	sub vcl_backend_response {
 		if (paren.match(beresp.http.foo)) {
 			set beresp.http.foo = "baz";
@@ -22,7 +28,14 @@ varnish v1 -vcl+backend {
 client c1 {
 	txreq
 	rxresp 
+	expect resp.status == 200
 	expect resp.http.content-length == 6
 	expect resp.http.foo == "bar"
 	expect resp.http.baz == "quux"
 } -run
+
+logexpect l1 -v v1 -d 1 -g vxid -q "VCL_Error" {
+	expect 0 * Begin req
+	expect * = VCL_Error "vmod re: error compiling regex:"
+	expect * = End
+} -run

src/tests/c08.vtc

+varnishtest "backrefs always fail when compilation failed"
+
+server s1 {
+	rxreq
+	txresp -hdr "Foo: bar" -body "1111\n"
+} -start
+
+varnish v1 -vcl+backend {
+	import re from "${vmod_topbuild}/src/.libs/libvmod_re.so";
+
+	sub vcl_init {
+		new paren = re.regex("(");
+		new parend = re.regex("");
+	}
+
+	sub vcl_deliver {
+	        set resp.http.paren = paren.failed();
+
+		/* match fails */
+		if (paren.match(resp.http.foo)) {
+			set resp.http.match = "success";
+		}
+		/* ... so all backrefs fail */
+		set resp.http.paren0 = paren.backref(0, "fallback0");
+		set resp.http.paren1 = paren.backref(1, "fallback1");
+		set resp.http.paren2 = paren.backref(2, "fallback2");
+		set resp.http.paren3 = paren.backref(3, "fallback3");
+		set resp.http.paren4 = paren.backref(4, "fallback4");
+		set resp.http.paren5 = paren.backref(5, "fallback5");
+		set resp.http.paren6 = paren.backref(6, "fallback6");
+		set resp.http.paren7 = paren.backref(7, "fallback7");
+		set resp.http.paren8 = paren.backref(8, "fallback8");
+		set resp.http.paren9 = paren.backref(9, "fallback9");
+		set resp.http.paren10 = paren.backref(10, "fallback10");
+
+		if (paren.match_dyn("(bar)", resp.http.foo)) {
+		   # dynamic matches do not affect failed()
+		   set resp.http.parend = paren.failed();
+		}
+
+		/* compilation fails */
+		if (parend.match_dyn(")", resp.http.foo)) {
+			set resp.http.matchd = "success";
+		}
+		/* ... so all backrefs fail */
+		set resp.http.paren0d = parend.backref(0, "fallback0");
+		set resp.http.paren1d = parend.backref(1, "fallback1");
+		set resp.http.paren2d = parend.backref(2, "fallback2");
+		set resp.http.paren3d = parend.backref(3, "fallback3");
+		set resp.http.paren4d = parend.backref(4, "fallback4");
+		set resp.http.paren5d = parend.backref(5, "fallback5");
+		set resp.http.paren6d = parend.backref(6, "fallback6");
+		set resp.http.paren7d = parend.backref(7, "fallback7");
+		set resp.http.paren8d = parend.backref(8, "fallback8");
+		set resp.http.paren9d = parend.backref(9, "fallback9");
+		set resp.http.paren10d = parend.backref(10, "fallback10");
+	}
+
+} -start
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.http.paren == "true"
+	expect resp.http.match == <undef>
+	expect resp.http.paren0 == "fallback0"
+	expect resp.http.paren1 == "fallback1"
+	expect resp.http.paren2 == "fallback2"
+	expect resp.http.paren3 == "fallback3"
+	expect resp.http.paren4 == "fallback4"
+	expect resp.http.paren5 == "fallback5"
+	expect resp.http.paren6 == "fallback6"
+	expect resp.http.paren7 == "fallback7"
+	expect resp.http.paren8 == "fallback8"
+	expect resp.http.paren9 == "fallback9"
+	expect resp.http.paren10 == "fallback10"
+
+	expect resp.http.parend == "true"
+	expect resp.http.matchd == <undef>
+	expect resp.http.paren0d == "fallback0"
+	expect resp.http.paren1d == "fallback1"
+	expect resp.http.paren2d == "fallback2"
+	expect resp.http.paren3d == "fallback3"
+	expect resp.http.paren4d == "fallback4"
+	expect resp.http.paren5d == "fallback5"
+	expect resp.http.paren6d == "fallback6"
+	expect resp.http.paren7d == "fallback7"
+	expect resp.http.paren8d == "fallback8"
+	expect resp.http.paren9d == "fallback9"
+	expect resp.http.paren10d == "fallback10"
+} -run
+
+logexpect l1 -v v1 -d 1 -g vxid -q "VCL_Error" {
+	expect 0 * Begin req
+
+	# from match()
+	expect * = VCL_Error "^vmod re: error compiling regex:"
+
+	# from match_dyn()
+	expect * = VCL_Error "^vmod re: error compiling regex"
+
+	# from the backref() calls after match_dyn()
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+	expect * = VCL_Error "^vmod re: backref called without prior match$"
+
+	expect * = End
+} -run

src/vmod_re.c

@@ -107,6 +107,14 @@ vmod_regex__init(const struct vrt_ctx *ctx, struct vmod_re_regex **rep,
 #endif
 }
 
+VCL_BOOL
+vmod_regex_failed(const struct vrt_ctx *ctx, struct vmod_re_regex *re)
+{
+	(void) ctx;
+	CHECK_OBJ_NOTNULL(re, VMOD_RE_REGEX_MAGIC);
+	return (re->error != NULL);
+}
+
 VCL_VOID
 vmod_regex__fini(struct vmod_re_regex **rep)
 {

src/vmod_re.vcc

@@ -115,7 +115,15 @@ Description
 	for extracting backreferences.
 
 Example
-	new myregex = re.regex("\bmax-age\s*=\s*(\d+)");
+	``new myregex = re.regex("\bmax-age\s*=\s*(\d+)");``
+
+$Method BOOL .failed()
+
+Description
+	Returns true if regex compilation in the constructor failed.
+
+Example
+	``if (myregex.failed()) { # ...``
 
 $Method BOOL .match(STRING)