Bugfix sub object for subroutine names with non-alphanum characters.

These are formatted as for VCC_PrintCName() in libvcc.

README.rst

@@ -155,4 +155,3 @@ COPYRIGHT
  
   See LICENSE
  
-

src/tests/sub.vtc

@@ -10,6 +10,8 @@ varnish v1 -arg "-p vcc_err_unref=off" -vcl {
                 new s = dispatch.sub();
                 s.add(0, "sub1");
                 s.add(1, "sub2");
+                s.add(2, "sub_underscore");
+                s.add(3, "sub-hyphen");
         }
 
 	sub sub1 {
@@ -20,13 +22,30 @@ varnish v1 -arg "-p vcc_err_unref=off" -vcl {
 		set req.http.Sub = "sub2";
 	}
 
+	sub sub_underscore {
+		set req.http.Sub = "sub_underscore";
+	}
+
+	sub sub-hyphen {
+		set req.http.Sub = "sub-hyphen";
+	}
+
 	sub vcl_recv {
                 if (req.url == "/0") {
                         s.call(0);
                 }
-                if (req.url == "/1") {
+                elsif (req.url == "/1") {
                         s.call(1);
                 }
+                elsif (req.url == "/2") {
+                        s.call(2);
+                }
+                elsif (req.url == "/3") {
+                        s.call(3);
+                }
+		else {
+			return(fail);
+		}
 		return(synth(200));
         }
 
@@ -44,6 +63,14 @@ client c1 {
         rxresp
         expect resp.status == 200
         expect resp.http.Sub == "sub2"
+        txreq -url "/2"
+        rxresp
+        expect resp.status == 200
+        expect resp.http.Sub == "sub_underscore"
+        txreq -url "/3"
+        rxresp
+        expect resp.status == 200
+        expect resp.http.Sub == "sub-hyphen"
 } -run
 
 varnish v1 -errvcl {vmod dispatch error: s.add(0): subroutine name is empty} {

src/vmod_dispatch.c

@@ -34,6 +34,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <dlfcn.h>
+#include <ctype.h>
+#include <stdio.h>
 
 #include "cache/cache.h"
 #include "vcl.h"
@@ -49,6 +51,9 @@
 
 #define INIT_BITS (64)
 
+#define CFUNC_PREFIX ("VGC_function_")
+#define CFUNC_PREFIX_LEN (sizeof(CFUNC_PREFIX) - 1)
+
 struct vmod_dispatch_label {
 	unsigned	magic;
 #define VMOD_DISPATCH_LABEL_MAGIC 0x44515cd0
@@ -236,9 +241,9 @@ VCL_VOID
 vmod_sub_add(VRT_CTX, struct vmod_dispatch_sub *sub, VCL_INT n,
 	     VCL_STRING subname)
 {
-	uintptr_t snap;
 	struct vmod_dispatch_vcl *vcl;
-	char *funcname;
+	char *funcname, *f;
+	unsigned len, l = 0;
 	vcl_func_f *vcl_func;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
@@ -260,18 +265,50 @@ vmod_sub_add(VRT_CTX, struct vmod_dispatch_sub *sub, VCL_INT n,
 		     n, subname);
 		return;
 	}
-	snap = WS_Snapshot(ctx->ws);
-	if ((funcname = WS_Printf(ctx->ws, "VGC_function_%s", subname))
-	    == NULL) {
+	len = WS_Reserve(ctx->ws, 0);
+	if (len <= CFUNC_PREFIX_LEN) {
+		VERR(ctx, "%s.add(%ld, %s): insufficient workspace for "
+		     "internal C function prefix", sub->vcl_name, n, subname);
+		WS_Release(ctx->ws, 0);
+		return;
+	}
+	funcname = WS_Front(ctx->ws);
+	strcpy(funcname, CFUNC_PREFIX);
+	f = funcname + CFUNC_PREFIX_LEN;
+
+	/* cf. VCC_PrintCName() */
+	for (const char *s = subname; *s; s++) {
+		if (*s < 0 || !isalnum(*s)) {
+			if (l + 4 >= len) {
+				l = 0;
+				break;
+			}
+			sprintf(f, "_%02x_", *s);
+			f += 4;
+			l += 4;
+		}
+		else {
+			if (l == len) {
+				l = 0;
+				break;
+			}
+			*f++ = *s;
+			l++;
+		}
+	}
+	if (l == 0) {
 		VERR(ctx, "%s.add(%ld, %s): insufficient workspace for "
 		     "internal C function name", sub->vcl_name, n, subname);
+		WS_Release(ctx->ws, 0);
 		return;
 	}
+	funcname[CFUNC_PREFIX_LEN + l] = '\0';
 	vcl_func = dlsym(vcl->dlh, funcname);
-	WS_Reset(ctx->ws, snap);
+	WS_Release(ctx->ws, 0);
 	if (vcl_func == NULL) {
-		VERR(ctx, "%s.add(%ld, %s): VCL subroutine not found: %s",
-		     sub->vcl_name, n, subname, dlerror());
+		VERR(ctx, "%s.add(%ld, %s): VCL subroutine not found "
+		     "(C function %s): %s", sub->vcl_name, n, subname, funcname,
+		     dlerror());
 		return;
 	}
 	if (n >= sub->nsubs)