Nikolay Sivov : wshom.ocx: Fix string length returned from Check returned BSTR length.

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: 901742c35a18a34875eb0e1da2def8d11a6db6a8
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=901742c35a18a34875eb0e1da...

Author: Nikolay Sivov 
Date:   Mon Mar  4 15:52:25 2019 +0300

wshom.ocx: Fix string length returned from Check returned BSTR length.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=46754
Signed-off-by: Nikolay Sivov 
Signed-off-by: Alexandre Julliard 
(cherry picked from commit 1866fd659a320c33790aa67fa9b66f032b8269a8)
Signed-off-by: Michael Stefaniuc

---

dlls/wshom.ocx/shell.c       | 14 ++++++++------
 dlls/wshom.ocx/tests/wshom.c | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/dlls/wshom.ocx/shell.c b/dlls/wshom.ocx/shell.c
index ca4f7ff..57f1746 100644
--- a/dlls/wshom.ocx/shell.c
+++ b/dlls/wshom.ocx/shell.c
@@ -455,14 +455,16 @@ static HRESULT WINAPI WshEnvironment_get_Item(IWshEnvironment *iface, BSTR name,
         return E_POINTER;

len = GetEnvironmentVariableW(name, NULL, 0);
-    *value = SysAllocStringLen(NULL, len);
-    if (!*value)
-        return E_OUTOFMEMORY;
-
     if (len)
-        GetEnvironmentVariableW(name, *value, len+1);
+    {
+        *value = SysAllocStringLen(NULL, len - 1);
+        if (*value)
+            GetEnvironmentVariableW(name, *value, len);
+    }
+    else
+        *value = SysAllocStringLen(NULL, 0);

-    return S_OK;
+    return *value ? S_OK : E_OUTOFMEMORY;
 }

static HRESULT WINAPI WshEnvironment_put_Item(IWshEnvironment *iface, BSTR name, BSTR value)
diff --git a/dlls/wshom.ocx/tests/wshom.c b/dlls/wshom.ocx/tests/wshom.c
index c1f9519..c00f7ab 100644
--- a/dlls/wshom.ocx/tests/wshom.c
+++ b/dlls/wshom.ocx/tests/wshom.c
@@ -56,6 +56,13 @@ static void _test_provideclassinfo(IDispatch *disp, const GUID *guid, int line)
     ITypeInfo_Release(ti);
 }

+#define CHECK_BSTR_LENGTH(str) check_bstr_length(str, __LINE__)
+static void check_bstr_length(BSTR str, int line)
+{
+    ok_(__FILE__, line)(SysStringLen(str) == lstrlenW(str), "Unexpected string length %u vs %u.\n",
+            SysStringLen(str), lstrlenW(str));
+}
+
 static void test_wshshell(void)
 {
     static const WCHAR notepadW[] = {'n','o','t','e','p','a','d','.','e','x','e',0};
@@ -156,6 +163,7 @@ static void test_wshshell(void)
     hr = IWshCollection_Item(coll, &arg, &res);
     EXPECT_HR(hr, S_OK);
     ok(V_VT(&res) == VT_BSTR, "got res type %d\n", V_VT(&res));
+    CHECK_BSTR_LENGTH(V_BSTR(&res));
     SysFreeString(str);
     VariantClear(&res);

@@ -211,6 +219,7 @@ static void test_wshshell(void)
     hr = IWshEnvironment_get_Item(env, str, &ret);
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(ret && *ret == 0, "got %s\n", wine_dbgstr_w(ret));
+    CHECK_BSTR_LENGTH(ret);
     SysFreeString(ret);
     SysFreeString(str);

@@ -219,6 +228,7 @@ static void test_wshshell(void)
     hr = IWshEnvironment_get_Item(env, str, &ret);
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(ret && *ret != 0, "got %s\n", wine_dbgstr_w(ret));
+    CHECK_BSTR_LENGTH(ret);
     SysFreeString(ret);
     SysFreeString(str);

@@ -304,6 +314,7 @@ static void test_wshshell(void)
     hr = IWshShell3_get_CurrentDirectory(sh3, &str);
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(str && str[0] != 0, "got empty string\n");
+    CHECK_BSTR_LENGTH(str);
     SysFreeString(str);

hr = IWshShell3_put_CurrentDirectory(sh3, NULL);
@@ -440,6 +451,7 @@ static void test_registry(void)
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(V_VT(&value) == VT_BSTR, "got %d\n", V_VT(&value));
     ok(!lstrcmpW(V_BSTR(&value), foobarW), "got %s\n", wine_dbgstr_w(V_BSTR(&value)));
+    CHECK_BSTR_LENGTH(V_BSTR(&value));
     VariantClear(&value);
     SysFreeString(name);

@@ -452,6 +464,7 @@ static void test_registry(void)
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(V_VT(&value) == VT_BSTR, "got %d\n", V_VT(&value));
     ok(SysStringLen(V_BSTR(&value)) == 6, "len %d\n", SysStringLen(V_BSTR(&value)));
+    CHECK_BSTR_LENGTH(V_BSTR(&value));
     VariantClear(&value);
     SysFreeString(name);

@@ -528,6 +541,7 @@ static void test_registry(void)
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(V_VT(&v) == VT_BSTR, "got %d\n", V_VT(&v));
     ok(!lstrcmpW(V_BSTR(&v), fooW), "got %s\n", wine_dbgstr_w(V_BSTR(&v)));
+    CHECK_BSTR_LENGTH(V_BSTR(&v));
     VariantClear(&v);
     VariantClear(&value);