CLEANUP: Use `isttest()` and `istfree()`

This adjusts a few locations to make use of `isttest()` and `istfree()`.
diff --git a/src/fcgi-app.c b/src/fcgi-app.c
index 5d26580..8472cf5 100644
--- a/src/fcgi-app.c
+++ b/src/fcgi-app.c
@@ -838,9 +838,9 @@
 		}
 		if (alertif_too_many_args_idx(0, 1, file, linenum, args, &err_code))
 			goto out;
-		free(curapp->docroot.ptr);
+		istfree(&curapp->docroot);
 		curapp->docroot = ist2(strdup(args[1]), strlen(args[1]));
-		if (!curapp->docroot.ptr) {
+		if (!isttest(curapp->docroot)) {
 			ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
 			err_code |= ERR_ALERT | ERR_ABORT;
 		}
@@ -871,9 +871,9 @@
 		}
 		if (alertif_too_many_args_idx(0, 1, file, linenum, args, &err_code))
 			goto out;
-		free(curapp->index.ptr);
+		istfree(&curapp->index);
 		curapp->index = ist2(strdup(args[1]), strlen(args[1]));
-		if (!curapp->index.ptr) {
+		if (!isttest(curapp->index)) {
 			ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
 			err_code |= ERR_ALERT | ERR_ABORT;
 		}
@@ -1070,8 +1070,8 @@
 		struct fcgi_rule_conf *rule, *back;
 
 		free(curapp->name);
-		free(curapp->docroot.ptr);
-		free(curapp->index.ptr);
+		istfree(&curapp->docroot);
+		istfree(&curapp->index);
 		regex_free(curapp->pathinfo_re);
 		free(curapp->conf.file);
 
diff --git a/src/hlua.c b/src/hlua.c
index d8e538b..4043e29 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -3889,7 +3889,7 @@
 	lua_settable(L, -3);
 
 	path = http_get_path(htx_sl_req_uri(sl));
-	if (path.ptr) {
+	if (isttest(path)) {
 		char *p, *q, *end;
 
 		p = path.ptr;
diff --git a/src/hpack-dec.c b/src/hpack-dec.c
index b4d8f0d..fa25ac4 100644
--- a/src/hpack-dec.c
+++ b/src/hpack-dec.c
@@ -191,7 +191,7 @@
 			}
 
 			value = hpack_alloc_string(tmp, idx, hpack_idx_to_value(dht, idx));
-			if (!value.ptr) {
+			if (!isttest(value)) {
 				hpack_debug_printf("##ERR@%d##\n", __LINE__);
 				ret = -HPACK_ERR_TOO_LARGE;
 				goto leave;
@@ -202,7 +202,7 @@
 
 			if (!name.len) {
 				name = hpack_alloc_string(tmp, idx, hpack_idx_to_name(dht, idx));
-				if (!name.ptr) {
+				if (!isttest(name)) {
 					hpack_debug_printf("##ERR@%d##\n", __LINE__);
 					ret = -HPACK_ERR_TOO_LARGE;
 					goto leave;
@@ -412,7 +412,7 @@
 
 			if (!name.len) {
 				name = hpack_alloc_string(tmp, idx, hpack_idx_to_name(dht, idx));
-				if (!name.ptr) {
+				if (!isttest(name)) {
 					hpack_debug_printf("##ERR@%d##\n", __LINE__);
 					ret = -HPACK_ERR_TOO_LARGE;
 					goto leave;
@@ -444,7 +444,7 @@
 		}
 
 		hpack_debug_printf("\e[1;34m%s\e[0m: ",
-				   name.ptr ? istpad(trash.area, name).ptr : h2_phdr_to_str(name.len));
+				   isttest(name) ? istpad(trash.area, name).ptr : h2_phdr_to_str(name.len));
 
 		hpack_debug_printf("\e[1;35m%s\e[0m [mustidx=%d, used=%d] [n=(%p,%d) v=(%p,%d)]\n",
 				   istpad(trash.area, value).ptr, must_index,
diff --git a/src/http_act.c b/src/http_act.c
index 9bfa7eb..7c16c33 100644
--- a/src/http_act.c
+++ b/src/http_act.c
@@ -56,8 +56,7 @@
 {
 	struct logformat_node *lf, *lfb;
 
-	if (rule->arg.http.str.ptr)
-		free(rule->arg.http.str.ptr);
+	istfree(&rule->arg.http.str);
 	if (rule->arg.http.re)
 		regex_free(rule->arg.http.re);
 	list_for_each_entry_safe(lf, lfb, &rule->arg.http.fmt, list) {
@@ -1257,7 +1256,7 @@
 
 	cur_arg++;
 	if (!parse_logformat_string(args[cur_arg], px, &rule->arg.http.fmt, LOG_OPT_HTTP, cap, err)) {
-		free(rule->arg.http.str.ptr);
+		istfree(&rule->arg.http.str);
 		return ACT_RET_PRS_ERR;
 	}
 
@@ -1351,7 +1350,7 @@
 
 	cur_arg++;
 	if (!(rule->arg.http.re = regex_comp(args[cur_arg], 1, 1, err))) {
-		free(rule->arg.http.str.ptr);
+		istfree(&rule->arg.http.str);
 		return ACT_RET_PRS_ERR;
 	}
 
@@ -1366,7 +1365,7 @@
 
 	cur_arg++;
 	if (!parse_logformat_string(args[cur_arg], px, &rule->arg.http.fmt, LOG_OPT_HTTP, cap, err)) {
-		free(rule->arg.http.str.ptr);
+		istfree(&rule->arg.http.str);
 		regex_free(rule->arg.http.re);
 		return ACT_RET_PRS_ERR;
 	}
@@ -1829,7 +1828,7 @@
 				free(lf->arg);
 				free(lf);
 			}
-			free(hdr->name.ptr);
+			istfree(&hdr->name);
 			free(hdr);
 		}
 		free(rule->arg.http_return.hdrs);
@@ -2295,7 +2294,7 @@
 					free(lf->arg);
 					free(lf);
 				}
-				free(hdr->name.ptr);
+				istfree(&hdr->name);
 				free(hdr);
 			}
 		}
@@ -2366,7 +2365,7 @@
 					free(lf->arg);
 					free(lf);
 				}
-				free(hdr->name.ptr);
+				istfree(&hdr->name);
 				free(hdr);
 			}
 		}
@@ -2444,7 +2443,7 @@
 				free(lf->arg);
 				free(lf);
 			}
-			free(hdr->name.ptr);
+			istfree(&hdr->name);
 			free(hdr);
 		}
 		free(hdrs);
diff --git a/src/http_ana.c b/src/http_ana.c
index e268d4c..a970660 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -2503,7 +2503,7 @@
 			sl = http_get_stline(htx);
 			path = http_get_path(htx_sl_req_uri(sl));
 			/* build message using path */
-			if (path.ptr) {
+			if (isttest(path)) {
 				if (rule->flags & REDIRECT_FLAG_DROP_QS) {
 					int qs = 0;
 					while (qs < path.len) {
@@ -2551,7 +2551,7 @@
 			sl = http_get_stline(htx);
 			path = http_get_path(htx_sl_req_uri(sl));
 			/* build message using path */
-			if (path.ptr) {
+			if (isttest(path)) {
 				if (rule->flags & REDIRECT_FLAG_DROP_QS) {
 					int qs = 0;
 					while (qs < path.len) {
@@ -4252,7 +4252,7 @@
 	htx = htxbuf(&req->buf);
 	sl = http_get_stline(htx);
 	path = http_get_path(htx_sl_req_uri(sl));
-	if (!path.ptr)
+	if (!isttest(path))
 		return;
 
 	if (!chunk_memcat(&trash, path.ptr, path.len))
diff --git a/src/http_fetch.c b/src/http_fetch.c
index dbbb5ec..9113b5e 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -987,7 +987,7 @@
 
 	sl = http_get_stline(htx);
 	path = iststop(http_get_path(htx_sl_req_uri(sl)), '?');
-	if (!path.ptr)
+	if (!isttest(path))
 		return 0;
 
 	/* OK, we got the '/' ! */
@@ -1028,7 +1028,7 @@
 	/* now retrieve the path */
 	sl = http_get_stline(htx);
 	path = http_get_path(htx_sl_req_uri(sl));
-	if (path.ptr) {
+	if (isttest(path)) {
 		size_t len;
 
 		for (len = 0; len < path.len && *(path.ptr + len) != '?'; len++)
@@ -1074,7 +1074,7 @@
 	/* now retrieve the path */
 	sl = http_get_stline(htx);
 	path = http_get_path(htx_sl_req_uri(sl));
-	if (path.ptr) {
+	if (isttest(path)) {
 		size_t len;
 
 		for (len = 0; len < path.len && *(path.ptr + len) != '?'; len++)
@@ -1422,7 +1422,7 @@
 	path.len = ptr - path.ptr;
 
 	path = http_get_path(path);
-	if (!path.ptr)
+	if (!isttest(path))
 		return 0;
 
 	smp->data.u.str.area = path.ptr;
diff --git a/src/http_htx.c b/src/http_htx.c
index 8157eb5..0e68695 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -111,7 +111,7 @@
 	if (blk) {
 		char *p;
 
-		if (!ctx->value.ptr)
+		if (!isttest(ctx->value))
 			goto rescan_hdr;
 		if (full)
 			goto next_blk;
@@ -309,7 +309,7 @@
 
 	uri = htx_sl_req_uri(sl);
 	p = http_get_path(uri);
-	if (!p.ptr)
+	if (!isttest(p))
 		p = uri;
 	while (plen < p.len && *(p.ptr + plen) != '?')
 		plen++;
diff --git a/src/mux_h1.c b/src/mux_h1.c
index 2e2dbf9..7260629 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -2853,7 +2853,7 @@
 	entry->name.len = strlen(to);
 	if (!entry->node.key || !entry->name.ptr) {
 		free(entry->node.key);
-		free(entry->name.ptr);
+		istfree(&entry->name);
 		free(entry);
 		memprintf(err, "out of memory");
 		return -1;
@@ -2873,7 +2873,7 @@
 		ebpt_delete(node);
 		entry = container_of(node, struct h1_hdr_entry, node);
 		free(entry->node.key);
-		free(entry->name.ptr);
+		istfree(&entry->name);
 		free(entry);
 		node = next;
 	}