msi: Reject NULL or empty patch package parameter in MsiApplyPatch.

[Hans Leidekker]

diff --git a/dlls/msi/msi.c b/dlls/msi/msi.c
index 58a1856..ed8b4ab 100644
--- a/dlls/msi/msi.c
+++ b/dlls/msi/msi.c
@@ -315,6 +315,9 @@ static UINT MSI_ApplyPatchW(LPCWSTR szPatchPackage, LPCWSTR szProductCode, LPCWS
     static const WCHAR patcheq[] = {'P','A','T','C','H','=',0};
     static WCHAR empty[] = {0};
 
+    if (!szPatchPackage || !szPatchPackage[0])
+        return ERROR_INVALID_PARAMETER;
+
     if (!szProductCode)
     {
         r = MsiOpenDatabaseW(szPatchPackage, MSIDBOPEN_READONLY, &patch);
diff --git a/dlls/msi/tests/package.c b/dlls/msi/tests/package.c
index a7e5261..308a9cc 100644
--- a/dlls/msi/tests/package.c
+++ b/dlls/msi/tests/package.c
@@ -11604,6 +11604,17 @@ static void test_MsiApplyMultiplePatches(void)
     todo_wine ok(r == ERROR_FILE_NOT_FOUND, "Expected ERROR_FILE_NOT_FOUND, got %u\n", r);
 }
 
+static void test_MsiApplyPatch(void)
+{
+    UINT r;
+
+    r = MsiApplyPatch(NULL, NULL, INSTALLTYPE_DEFAULT, NULL);
+    ok(r == ERROR_INVALID_PARAMETER, "Expected ERROR_INVALID_PARAMETER, got %u\n", r);
+
+    r = MsiApplyPatch("", NULL, INSTALLTYPE_DEFAULT, NULL);
+    ok(r == ERROR_INVALID_PARAMETER, "Expected ERROR_INVALID_PARAMETER, got %u\n", r);
+}
+
 START_TEST(package)
 {
     HMODULE hmsi = GetModuleHandleA("msi.dll");
@@ -11642,4 +11653,5 @@ START_TEST(package)
     test_MsiGetProductProperty();
     test_MsiSetProperty();
     test_MsiApplyMultiplePatches();
+    test_MsiApplyPatch();
 }