r15841: grab talloc fixes (current up to r15838)

3 files changed, 39 insertions, 3 deletions

diff --git a/WHATSNEW.txt b/WHATSNEW.txt
index 898007a5a8d..a6ff0bc0628 100644
--- a/WHATSNEW.txt
+++ b/WHATSNEW.txt
@@ -61,6 +61,8 @@ o   Jeremy Allison <jra@samba.org>
     * Instruct winbindd to ignore fd_set when select() returns -1.
     * BUG 3779: Make nmbd udp sockets non-blocking to prevent problem
       with select returning true but no data being available.
+    * Backport talloc_steal() fixes from SAMBA_4_0 (original fixes by 
+      Andrew Tridgell).
 
 
 o   Timur Bakeyev <timur@com.bat.ru>
diff --git a/source/include/talloc.h b/source/include/talloc.h
index 1001a951702..17032ac7acc 100644
--- a/source/include/talloc.h
+++ b/source/include/talloc.h
@@ -139,6 +139,7 @@ void *talloc_autofree_context(void);
 size_t talloc_get_size(const void *ctx);
 void *talloc_find_parent_byname(const void *ctx, const char *name);
 void talloc_show_parents(const void *context, FILE *file);
+int talloc_is_parent(const void *context, const char *ptr);
 
 #endif
 
diff --git a/source/lib/talloc.c b/source/lib/talloc.c
index c1116155065..51087ef9791 100644
--- a/source/lib/talloc.c
+++ b/source/lib/talloc.c
@@ -540,7 +540,13 @@ int talloc_free(void *ptr)
 	tc = talloc_chunk_from_ptr(ptr);
 
 	if (tc->refs) {
+		int is_child;
+		struct talloc_reference_handle *handle = tc->refs;
+		is_child = talloc_is_parent(handle, handle->ptr);
 		talloc_reference_destructor(tc->refs);
+		if (is_child) {
+			return talloc_free(ptr);
+		}
 		return -1;
 	}
 
@@ -690,7 +696,7 @@ void *talloc_steal(const void *new_ctx, const void *ptr)
 
 	new_tc = talloc_chunk_from_ptr(new_ctx);
 
-	if (tc == new_tc) {
+	if (tc == new_tc || tc->parent == new_tc) {
 		return discard_const_p(void, ptr);
 	}
 
@@ -1278,7 +1284,10 @@ void *talloc_find_parent_byname(const void *context, const char *name)
 			return TC_PTR_FROM_CHUNK(tc);
 		}
 		while (tc && tc->prev) tc = tc->prev;
-		tc = tc->parent;
+		if (tc) {
+			tc = tc->parent;
+		}
+
 	}
 	return NULL;
 }
@@ -1300,6 +1309,30 @@ void talloc_show_parents(const void *context, FILE *file)
 	while (tc) {
 		fprintf(file, "\t'%s'\n", talloc_get_name(TC_PTR_FROM_CHUNK(tc)));
 		while (tc && tc->prev) tc = tc->prev;
-		tc = tc->parent;
+		if (tc) {
+			tc = tc->parent;
+		}
 	}
 }
+
+/*
+  return 1 if ptr is a parent of context
+*/
+int talloc_is_parent(const void *context, const char *ptr)
+{
+	struct talloc_chunk *tc;
+
+	if (context == NULL) {
+		return 0;
+	}
+
+	tc = talloc_chunk_from_ptr(context);
+	while (tc) {
+		if (TC_PTR_FROM_CHUNK(tc) == ptr) return 1;
+		while (tc && tc->prev) tc = tc->prev;
+		if (tc) {
+			tc = tc->parent;
+		}
+	}
+	return 0;
+}