Alex Henrie : msi: Fix memory leak on realloc failure in create_diff_row_query (cppcheck).

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 3e231d0f36a56ce991c7edbb6ae7845094e8417e
URL:    https://gitlab.winehq.org/wine/wine/-/commit/3e231d0f36a56ce991c7edbb6ae7845...

Author: Alex Henrie 
Date:   Sun Dec 11 21:23:50 2022 -0700

msi: Fix memory leak on realloc failure in create_diff_row_query (cppcheck).

---

dlls/msi/database.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/dlls/msi/database.c b/dlls/msi/database.c
index c0845fbadcb..c50e34cc8cd 100644
--- a/dlls/msi/database.c
+++ b/dlls/msi/database.c
@@ -1412,7 +1412,7 @@ static LPWSTR get_key_value(MSIQUERY *view, LPCWSTR key, MSIRECORD *rec)
 static LPWSTR create_diff_row_query(MSIDATABASE *merge, MSIQUERY *view,
                                     LPWSTR table, MSIRECORD *rec)
 {
-    LPWSTR query = NULL, clause = NULL, val;
+    WCHAR *query = NULL, *clause = NULL, *new_clause, *val;
     LPCWSTR setptr, key;
     DWORD size, oldsize;
     MSIRECORD *keys;
@@ -1422,10 +1422,6 @@ static LPWSTR create_diff_row_query(MSIDATABASE *merge, MSIQUERY *view,
     if (r != ERROR_SUCCESS)
         return NULL;

-    clause = calloc(1, sizeof(WCHAR));
-    if (!clause)
-        goto done;
-
     size = 1;
     count = MSI_RecordGetFieldCount(keys);
     for (i = 1; i <= count; i++)
@@ -1440,12 +1436,13 @@ static LPWSTR create_diff_row_query(MSIDATABASE *merge, MSIQUERY *view,

oldsize = size;
         size += lstrlenW(setptr) + lstrlenW(key) + lstrlenW(val) - 4;
-        clause = realloc(clause, size * sizeof(WCHAR));
-        if (!clause)
+        new_clause = realloc(clause, size * sizeof(WCHAR));
+        if (!new_clause)
         {
             free(val);
             goto done;
         }
+        clause = new_clause;

swprintf(clause + oldsize - 1, size - (oldsize - 1), setptr, key, val);
         free(val);