Allow empty bootloader tag

ChangeLog

@@ -1,3 +1,9 @@
+Sat Sep 29 14:23:41 EST 2007 Daniel P. Berrange <berrange@redhat.com>
+
+	* src/sexpr.h, src/sexpr.c, src/xml.c, src/xend_internal.c: Allow
+	bootloader tag to be empty, to indicate use of default configured
+	bootloader path.
+
 Sat Sep 29 14:05:41 EST 2007 Daniel P. Berrange <berrange@redhat.com>
 
 	* src/sexpr.h, src/sexpr.c, src/virsh.c, src/xend_internal.c:

src/sexpr.c

@@ -404,17 +404,18 @@ string2sexpr(const char *buffer)
 
 
 /**
- * sexpr_lookup:
+ * sexpr_lookup_key:
  * @sexpr: a pointer to a parsed S-Expression
  * @node: a path for the sub expression to lookup in the S-Expression
  *
  * Search a sub expression in the S-Expression based on its path
+ * Returns the key node, rather than the data node.
  * NOTE: path are limited to 4096 bytes.
  *
  * Returns the pointer to the sub expression or NULL if not found.
  */
-struct sexpr *
-sexpr_lookup(struct sexpr *sexpr, const char *node)
+static struct sexpr *
+sexpr_lookup_key(struct sexpr *sexpr, const char *node)
 {
     char buffer[4096], *ptr, *token;
 
@@ -463,10 +464,57 @@ sexpr_lookup(struct sexpr *sexpr, const char *node)
         return NULL;
     }
 
-    if (sexpr->kind != SEXPR_CONS || sexpr->u.s.cdr->kind != SEXPR_CONS)
+    return sexpr;
+}
+
+/**
+ * sexpr_lookup:
+ * @sexpr: a pointer to a parsed S-Expression
+ * @node: a path for the sub expression to lookup in the S-Expression
+ *
+ * Search a sub expression in the S-Expression based on its path.
+ * NOTE: path are limited to 4096 bytes.
+ *
+ * Returns the pointer to the sub expression or NULL if not found.
+ */
+struct sexpr *
+sexpr_lookup(struct sexpr *sexpr, const char *node)
+{
+    struct sexpr *s = sexpr_lookup_key(sexpr, node);
+
+    if (s == NULL)
+	return NULL;
+
+    if (s->kind != SEXPR_CONS || s->u.s.cdr->kind != SEXPR_CONS)
         return NULL;
 
-    return sexpr->u.s.cdr;
+    return s->u.s.cdr;
+}
+
+/**
+ * sexpr_has:
+ * @sexpr: a pointer to a parsed S-Expression
+ * @node: a path for the sub expression to lookup in the S-Expression
+ *
+ * Search a sub expression in the S-Expression based on its path.
+ * NOTE: path are limited to 4096 bytes.
+ * NB, even if the key was found sexpr_lookup may return NULL if
+ * the corresponding value was empty
+ *
+ * Returns true if the key was found, false otherwise 
+ */
+int
+sexpr_has(struct sexpr *sexpr, const char *node)
+{
+    struct sexpr *s = sexpr_lookup_key(sexpr, node);
+
+    if (s == NULL)
+	return 0;
+
+    if (s->kind != SEXPR_CONS)
+        return 0;
+
+    return 1;
 }
 
 /**

src/sexpr.h

@@ -50,4 +50,5 @@ const char *sexpr_node(struct sexpr *sexpr, const char *node);
 const char *sexpr_fmt_node(struct sexpr *sexpr, const char *fmt, ...)
   ATTRIBUTE_FORMAT(printf,2,3);
 struct sexpr *sexpr_lookup(struct sexpr *sexpr, const char *node);
+int sexpr_has(struct sexpr *sexpr, const char *node);
 #endif

src/xend_internal.c

@@ -1402,6 +1402,9 @@ xend_parse_sexp_desc(virConnectPtr conn, struct sexpr *root, int xendConfigVersi
     if (tmp != NULL) {
         bootloader = 1;
         virBufferVSprintf(&buf, "  <bootloader>%s</bootloader>\n", tmp);
+    } else if (sexpr_has(root, "domain/bootloader")) {
+        bootloader = 1;
+        virBufferVSprintf(&buf, "  <bootloader/>\n");
     }
     tmp = sexpr_node(root, "domain/bootloader_args");
     if (tmp != NULL && bootloader) {
@@ -1414,7 +1417,8 @@ xend_parse_sexp_desc(virConnectPtr conn, struct sexpr *root, int xendConfigVersi
     if (domid != 0) {
         if (sexpr_lookup(root, "domain/image")) {
             hvm = sexpr_lookup(root, "domain/image/hvm") ? 1 : 0;
-            xend_parse_sexp_desc_os(conn, root, &buf, hvm, bootloader);
+            if (xend_parse_sexp_desc_os(conn, root, &buf, hvm, bootloader) < 0)
+                goto error;
         }
     }
 

src/xml.c

@@ -1179,6 +1179,14 @@ virDomainParseXMLDesc(virConnectPtr conn, const char *xmldesc, char **name, int
          */
         bootloader = 1;
 	free(str);
+    } else if (virXPathNumber("count(/domain/bootloader)", ctxt, &f) == 0 &&
+               (f > 0)) {
+        virBufferVSprintf(&buf, "(bootloader)");
+        /*
+         * if using a bootloader, the kernel and initrd strings are not
+         * significant and should be discarded
+         */
+        bootloader = 1;        
     }
 
     str = virXPathString("string(/domain/bootloader_args[1])", ctxt);