Francois Gouget : kernel32/tests: Improve the WideCharToMultiByte() null-termination and truncation tests.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 11934d2c92ad645cad739640a52151fbb112269b
URL:    https://gitlab.winehq.org/wine/wine/-/commit/11934d2c92ad645cad739640a52151f...

Author: Francois Gouget <fgouget(a)codeweavers.com>
Date:   Fri Apr  7 15:52:37 2023 +0200

kernel32/tests: Improve the WideCharToMultiByte() null-termination and truncation tests.

Check the content of the output buffer in addition to checking the
return value.
Also show that multibyte characters are not truncated when the output
buffer is too small.

---

 dlls/kernel32/tests/codepage.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/dlls/kernel32/tests/codepage.c b/dlls/kernel32/tests/codepage.c
index 0a5185d1804..08d2514e3e4 100644
--- a/dlls/kernel32/tests/codepage.c
+++ b/dlls/kernel32/tests/codepage.c
@@ -54,6 +54,7 @@ static void test_destination_buffer(void)
     len = WideCharToMultiByte(CP_ACP, 0, foobarW, -1, buffer, needed+1, NULL, NULL);
     ok( (len > 0), "returned %d with %lu and '%s' (expected '> 0')\n",
         len, GetLastError(), buffer);
+    ok(!lstrcmpA(buffer, "foobar"), "expected \"foobar\" got \"%s\"\n", buffer);
 
     memset(buffer, 'x', maxsize);
     buffer[maxsize] = '\0';
@@ -61,6 +62,7 @@ static void test_destination_buffer(void)
     len = WideCharToMultiByte(CP_ACP, 0, foobarW, -1, buffer, needed, NULL, NULL);
     ok( (len > 0), "returned %d with %lu and '%s' (expected '> 0')\n",
         len, GetLastError(), buffer);
+    ok(!lstrcmpA(buffer, "foobar"), "expected \"foobar\" got \"%s\"\n", buffer);
 
     memset(buffer, 'x', maxsize);
     buffer[maxsize] = '\0';
@@ -69,6 +71,8 @@ static void test_destination_buffer(void)
     ok( !len && (GetLastError() == ERROR_INSUFFICIENT_BUFFER),
         "returned %d with %lu and '%s' (expected '0' with "
         "ERROR_INSUFFICIENT_BUFFER)\n", len, GetLastError(), buffer);
+    ok(!strncmp(buffer, "foobar", 6), "expected \"foobar\" got \"%s\"\n", buffer);
+    ok(buffer[6] == 'x', "expected buf[5]=='x', got \"%s\"\n", buffer);
 
     memset(buffer, 'x', maxsize);
     buffer[maxsize] = '\0';
@@ -77,6 +81,8 @@ static void test_destination_buffer(void)
     ok( !len && (GetLastError() == ERROR_INSUFFICIENT_BUFFER),
         "returned %d with %lu and '%s' (expected '0' with "
         "ERROR_INSUFFICIENT_BUFFER)\n", len, GetLastError(), buffer);
+    ok(buffer[0] == 'f', "expected buf[1]=='f', got \"%s\"\n", buffer);
+    ok(buffer[1] == 'x', "expected buf[1]=='x', got \"%s\"\n", buffer);
 
     SetLastError(0xdeadbeef);
     len = WideCharToMultiByte(CP_ACP, 0, foobarW, -1, buffer, 0, NULL, NULL);
@@ -428,6 +434,23 @@ static void test_string_conversion(LPBOOL bUsedDefaultChar)
     ok(!strcmp(mbs, "\xf3\xe7\x3d\xa3\xbf\xa3\xbf\xa3\xbf"), "mbs is %s\n", mbs);
     if(bUsedDefaultChar) ok(*bUsedDefaultChar == TRUE, "bUsedDefaultChar is %d\n", *bUsedDefaultChar);
 
+    /* Show that characters are not truncated */
+    ZeroMemory(mbs, 5);
+    ret = WideCharToMultiByte(936, 0, dbwcs2, -1, mbs, 1, (const char *)default_char, bUsedDefaultChar);
+    ok(!ret, "ret is %d\n", ret);
+    ok(mbs[0] == '\0', "mbs is %s\n", mbs);
+    if(bUsedDefaultChar) ok(*bUsedDefaultChar == FALSE, "bUsedDefaultChar is %d\n", *bUsedDefaultChar);
+    ok(GetLastError() == ERROR_INSUFFICIENT_BUFFER, "GetLastError() is %lu\n", GetLastError());
+
+    /* And destination is not null-terminated even when too short */
+    FillMemory(mbs, 5, 'x');
+    mbs[5] = '\0';
+    ret = WideCharToMultiByte(936, 0, dbwcs2, -1, mbs, 2, (const char *)default_char, bUsedDefaultChar);
+    ok(!ret, "ret is %d\n", ret);
+    ok(!strcmp(mbs, "\xf3\xe7""xxx"), "mbs is %s\n", mbs);
+    if(bUsedDefaultChar) ok(*bUsedDefaultChar == FALSE, "bUsedDefaultChar is %d\n", *bUsedDefaultChar);
+    ok(GetLastError() == ERROR_INSUFFICIENT_BUFFER, "GetLastError() is %lu\n", GetLastError());
+
     /* Length-only tests */
     SetLastError(0xdeadbeef);
     ret = WideCharToMultiByte(1252, 0, &wc2, 1, NULL, 0, NULL, bUsedDefaultChar);