Index: qdepends.c
===================================================================
RCS file: /var/cvsroot/gentoo-projects/portage-utils/qdepends.c,v
retrieving revision 1.38
diff -u -p -r1.38 qdepends.c
--- qdepends.c	5 Jun 2006 11:43:30 -0000	1.38
+++ qdepends.c	9 Oct 2006 21:14:34 -0000
@@ -336,6 +336,12 @@ char *dep_flatten_tree(dep_node *root)
 	static char flat[8192];
 	size_t pos = 0;
 	_dep_flatten_tree(root, flat, &pos);
+	if (pos == 0) {
+		/* all the nodes were squashed ... for example:
+		 * USE=-selinux RDEPEND="selinux? ( sys-libs/libselinux )"
+		 */
+		return NULL;
+	}
 	flat[pos-1] = '\0';
 	return flat;
 }
@@ -383,6 +389,7 @@ int qdepends_main_vdb(const char *depend
 			if (i == argc)
 				continue;
 
+			IF_DEBUG(warn("matched %s/%s", dentry->d_name, de->d_name));
 			snprintf(buf, sizeof(buf), "%s%s/%s/%s/%s", portroot, portvdb,
 			         dentry->d_name, de->d_name, depend_file);
 
@@ -396,6 +403,7 @@ int qdepends_main_vdb(const char *depend
 				continue;
 			}
 
+			IF_DEBUG(warn("growing tree..."));
 			dep_tree = dep_grow_tree(depend);
 			if (dep_tree == NULL) continue;
 			IF_DEBUG(puts(depend));
@@ -431,7 +439,8 @@ int qdepends_main_vdb(const char *depend
 			}
 
 			/*dep_dump_tree(dep_tree);*/
-			printf("%s\n", dep_flatten_tree(dep_tree));
+			ptr = dep_flatten_tree(dep_tree);
+			printf("%s\n", (ptr == NULL ? "" : ptr));
 
 			dep_burn_tree(dep_tree);
 		}
@@ -470,16 +479,20 @@ int qdepends_vdb_deep(const char *depend
 			if (*de->d_name == '.')
 				continue;
 
+			IF_DEBUG(warn("matched %s/%s", dentry->d_name, de->d_name));
 			snprintf(buf, sizeof(buf), "%s%s/%s/%s/%s", portroot, portvdb,
 			         dentry->d_name, de->d_name, depend_file);
+
 			if (!eat_file(buf, depend, sizeof(depend))) {
 				warn("i'm such a fatty, could not eat_file(%s)", buf);
 				continue;
 			}
-			IF_DEBUG(puts(depend));
 
+			IF_DEBUG(warn("growing tree..."));
 			dep_tree = dep_grow_tree(depend);
 			if (dep_tree == NULL) continue;
+			IF_DEBUG(puts(depend));
+			IF_DEBUG(dep_dump_tree(dep_tree));
 
 			snprintf(buf, sizeof(buf), "%s%s/%s/%s/USE", portroot, portvdb,
 			         dentry->d_name, de->d_name);
@@ -497,7 +510,7 @@ int qdepends_vdb_deep(const char *depend
 			dep_prune_use(dep_tree, use);
 
 			ptr = dep_flatten_tree(dep_tree);
-			if (rematch(query, ptr, REG_EXTENDED) == 0) {
+			if (ptr && rematch(query, ptr, REG_EXTENDED) == 0) {
 				if (qdep_name_only) {
 					depend_atom *atom = NULL;
 					snprintf(buf, sizeof(buf), "%s/%s", dentry->d_name, de->d_name);
@@ -509,7 +522,7 @@ int qdepends_vdb_deep(const char *depend
 					printf("%s%s/%s%s%s%c", BOLD, dentry->d_name, BLUE, de->d_name, NORM, verbose ? ':' : '\n');
 				}
 				if (verbose)
-					printf(" %s\n", dep_flatten_tree(dep_tree));
+					printf(" %s\n", ptr);
 			}
 			dep_burn_tree(dep_tree);
 		}