msi: Simplify ITERATE_WriteEnvironmentString.

Now we only allocate enough memory to exactly match the size of the constructed string. Before, we were leaving some memory uninitialized and overwriting the allocated memory in certain circum.

msi: Simplify ITERATE_WriteEnvironmentString.
1b7238a9 · James Hawkins · Alexandre Julliard · be1b1605 · 1b7238a9
Commit 1b7238a9 authored Dec 15, 2009 by James Hawkins Committed by Alexandre Julliard Dec 16, 2009
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Showing with 39 additions and 29 deletions

action.c dlls/msi/action.c +39 -29

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--- a/dlls/msi/action.c
+++ b/dlls/msi/action.c
@@ -5013,7 +5013,24 @@ static UINT ITERATE_WriteEnvironmentString( MSIRECORD *rec, LPVOID param )
        (res == ERROR_SUCCESS && type != REG_SZ && type != REG_EXPAND_SZ))
        goto done;

-    if (res != ERROR_FILE_NOT_FOUND)
+    if ((res == ERROR_FILE_NOT_FOUND || !(flags & ENV_MOD_MASK)))
+    {
+        /* Nothing to do. */
+        if (!value)
+        {
+            res = ERROR_SUCCESS;
+            goto done;
+        }
+
+        size = (lstrlenW(value) + 1) * sizeof(WCHAR);
+        newval = strdupW(value);
+        if (!newval)
+        {
+            res = ERROR_OUTOFMEMORY;
+            goto done;
+        }
+    }
+    else
    {
        if (flags & ENV_ACT_SETABSENT)
        {
@@ -5038,8 +5055,18 @@ static UINT ITERATE_WriteEnvironmentString( MSIRECORD *rec, LPVOID param )
            goto done;
        }

-        size += (lstrlenW(value) + 1) * sizeof(WCHAR);
-        newval =  msi_alloc(size);
+        size = (lstrlenW(data) + 1) * sizeof(WCHAR);
+        if (flags & ENV_MOD_MASK)
+        {
+            DWORD mod_size;
+            int multiplier = 0;
+            if (flags & ENV_MOD_APPEND) multiplier++;
+            if (flags & ENV_MOD_PREFIX) multiplier++;
+            mod_size = (lstrlenW(value) + 1) * multiplier;
+            size += mod_size * sizeof(WCHAR);
+        }
+
+        newval = msi_alloc(size);
        ptr = newval;
        if (!newval)
        {
@@ -5047,37 +5074,20 @@ static UINT ITERATE_WriteEnvironmentString( MSIRECORD *rec, LPVOID param )
            goto done;
        }

-        if (!(flags & ENV_MOD_MASK))
-            lstrcpyW(newval, value);
-        else
+        if (flags & ENV_MOD_PREFIX)
        {
-            if (flags & ENV_MOD_PREFIX)
-            {
-                lstrcpyW(newval, value);
-                lstrcatW(newval, szSemiColon);
-                ptr = newval + lstrlenW(value) + 1;
-            }
+            lstrcpyW(newval, value);
+            lstrcatW(newval, szSemiColon);
+            ptr = newval + lstrlenW(value) + 1;
+        }

-            lstrcpyW(ptr, data);
+        lstrcpyW(ptr, data);

-            if (flags & ENV_MOD_APPEND)
-            {
-                lstrcatW(newval, szSemiColon);
-                lstrcatW(newval, value);
-            }
-        }
-    }
-    else if (value)
-    {
-        size = (lstrlenW(value) + 1) * sizeof(WCHAR);
-        newval = msi_alloc(size);
-        if (!newval)
+        if (flags & ENV_MOD_APPEND)
        {
-            res = ERROR_OUTOFMEMORY;
-            goto done;
+            lstrcatW(newval, szSemiColon);
+            lstrcatW(newval, value);
        }
-
-        lstrcpyW(newval, value);
    }

    if (newval)