Fix matches in subtrees.

This commit makes it possible to run wildcard matches in
subtrees, e.g. like this:

    grecs_match_first(grecs_find_node(tree, root_path), path, &match_buf);

Another effect is that it is possible to use grecs_match_next after
a successful recursion using the grecs_node_exact_match.  In other words,
grecs_match_next works well for both exact and wildcard matches, whatever
was the originating node in the tree.  (This is used in eclat.)

* src/grecs.h (grecs_match_buf_get_root): New proto.
(grecs_match_buf_set_root): New proto.
* src/lookup.c (grecs_match_buf) <root>: New member.
(grecs_match_buf_get_root)
(grecs_match_buf_set_root): New functions.
(grecs_match): Use root member of struct grecs_match_buf
to determine whether we hit root.
(grecs_match_buf_first): Initialize root.
* src/tree.c (grecs_tree_first_node): Allow for non-root
node as argument (no-op in this case).
* tests/glob04.at: new testcase.
* tests/glob05.at: new testcase.
* tests/Makefile.am: Add new files.
* tests/testsuite.at: Include new files.
* tests/gcfpeek.c: New option "-root", for testing
matches in subtrees.

1 files changed, 27 insertions, 13 deletions

diff --git a/src/lookup.c b/src/lookup.c
index 68fd5cf..1758104 100644
--- a/src/lookup.c
+++ b/src/lookup.c
@@ -150,11 +150,12 @@ grecs_value_match(struct grecs_value *pat, struct grecs_value *b, int flags)
 
 
 struct grecs_match_buf {
-	int argc;
-	char **argv;
-	int argi;
-	struct grecs_value **labelv;
-	struct grecs_node *node;
+	int argc;                      /* number of path components */
+	char **argv;                   /* array of path components */
+	int argi;                      /* Index of the current component */
+	struct grecs_value **labelv;   /* Component labels */
+	struct grecs_node *root;       /* Root node */
+	struct grecs_node *node;       /* Last found node */ 
 };
 
 #define ISWC(c,w) ((c)[0] == (w) && (c)[1] == 0)
@@ -209,6 +210,18 @@ grecs_match_buf_get_node(grecs_match_buf_t buf)
 	return buf->node;
 }
 
+struct grecs_node *
+grecs_match_buf_get_root(grecs_match_buf_t buf)
+{
+	return buf->root;
+}
+
+void
+grecs_match_buf_set_root(grecs_match_buf_t buf, struct grecs_node *root)
+{
+	buf->root = root;
+}
+
 static void
 grecs_match_buf_free_contents(struct grecs_match_buf *buf)
 {
@@ -488,6 +501,12 @@ grecs_node_from_path(const char *path, const char *value)
 
 
 static int
+is_root(struct grecs_match_buf *buf, struct grecs_node *node)
+{
+	return (buf->root == node || node->type == grecs_node_root);
+}
+	    
+static int
 grecs_match(struct grecs_match_buf *buf)
 {
 	struct grecs_node *node;
@@ -513,13 +532,12 @@ grecs_match(struct grecs_match_buf *buf)
 			wcard = 0;
 			node = node->up;
 			if (buf->argi-- == 0)
-				return !node ||
-					node->type == grecs_node_root;
+				return is_root(buf, node);
 		} else if (!wcard)
 			return 0;
 		else
 			node = node->up;
-		if (!node || node->type == grecs_node_root)
+		if (is_root(buf, node))
 			return ISWC(buf->argv[buf->argi], '*');
 	}
 	return 0;
@@ -543,6 +561,7 @@ grecs_match_buf_first(struct grecs_match_buf *buf, struct grecs_node *tree)
 	struct grecs_node *node;
 
 	buf->argi = 0;
+	buf->root = tree;
 	buf->node = grecs_tree_first_node(tree);
 	if (grecs_match(buf))
 		node = buf->node;
@@ -558,11 +577,6 @@ grecs_match_first(struct grecs_node *tree, const char *pattern,
 	struct grecs_node *node;
 	struct grecs_match_buf *buf;
 
-	if (tree->type != grecs_node_root) {
-		errno = EINVAL;
-		return NULL;
-	}
-	errno = 0;
 	if (strcmp(pattern, ".") == 0) {
 		*pbuf = NULL;
 		return tree;