From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 3 Jul 2014 16:38:13 +0000 (+0200)
Subject: data: Improved memory handling in data_copy().
X-Git-Tag: sysdb-0.3.0~89
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=6e5f65caf34e2171af701e25206d42186b7640ff;p=sysdb.git

data: Improved memory handling in data_copy().

Ensure that dynamic memory in the destination is freed before copying the new
data. That'll avoid that the caller has to use data_free_datum() first and
destroy previous data even if the copy fails.
---

diff --git a/src/core/data.c b/src/core/data.c
index dc2d0ae..beba5a7 100644
--- a/src/core/data.c
+++ b/src/core/data.c
@@ -65,6 +65,7 @@ sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src)
 			break;
 	}
 
+	sdb_data_free_datum(dst);
 	*dst = tmp;
 	return 0;
 } /* sdb_data_copy */
diff --git a/src/core/store.c b/src/core/store.c
index 3885e50..8b284e7 100644
--- a/src/core/store.c
+++ b/src/core/store.c
@@ -532,10 +532,8 @@ sdb_store_attribute(const char *hostname,
 
 	if (status >= 0) {
 		assert(updated_attr);
-		sdb_data_free_datum(&ATTR(updated_attr)->value);
-		if (sdb_data_copy(&ATTR(updated_attr)->value, value)) {
+		if (sdb_data_copy(&ATTR(updated_attr)->value, value))
 			status = -1;
-		}
 	}
 
 	pthread_rwlock_unlock(&host_lock);
diff --git a/src/include/core/data.h b/src/include/core/data.h
index 879af90..d6bf317 100644
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
@@ -81,7 +81,8 @@ typedef struct {
  * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
  * Any dynamic data (strings, binary data) is copied to newly allocated
  * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
- * stored in a datum.
+ * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
+ * in 'dst' will be freed.
  *
  * Returns:
  *  - 0 on success