[tarantool-patches] [PATCH v1 2/3] sql: fix sql_vdbe_mem_alloc_region result memory

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

The function sql_vdbe_mem_alloc_region that constructing the
value of Vdbe Mem object used to change only flags responsible
for it's type.
It is also required to grind old flags, as their combination may
be invalid.
In a typical Vdbe scenario, OP_MakeRecord and OP_RowData make
memory release with sqlite3VdbeMemRelease and allocation
on region with sql_vdbe_mem_alloc_region call. An integrity
assert based on sqlite3VdbeCheckMemInvariants would fire here
because of contradictory combination of flags
MEM_Static | (MEM_Blob | MEM_Ephem).

Needed for #3850
---
 src/box/sql/vdbeaux.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/box/sql/vdbeaux.c b/src/box/sql/vdbeaux.c
index fc805e3aa..d477662a4 100644
--- a/src/box/sql/vdbeaux.c
+++ b/src/box/sql/vdbeaux.c
@@ -3231,7 +3231,8 @@ sql_vdbe_mem_alloc_region(Mem *vdbe_mem, uint32_t size)
 	vdbe_mem->z = region_alloc(&fiber()->gc, size);
 	if (vdbe_mem->z == NULL)
 		return SQLITE_NOMEM;
-	MemSetTypeFlag(vdbe_mem, MEM_Blob | MEM_Ephem);
+	vdbe_mem->flags = MEM_Ephem | MEM_Blob;
+	assert(sqlite3VdbeCheckMemInvariants(vdbe_mem));
 	return SQLITE_OK;
 }
 
-- 
2.19.2