winspool: Return ERROR_MORE_DATA, when the app probe for the needed buffer size.

dlls/winspool.drv/info.c

@@ -5367,6 +5367,8 @@ DWORD WINAPI GetPrinterDataExA(HANDLE hPrinter, LPCSTR pKeyName,
     ret = RegOpenKeyW(HKEY_LOCAL_MACHINE, PrintersW, &hkeyPrinters);
     if (ret) return ret;
 
+    TRACE("printer->name: %s\n", debugstr_w(printer->name));
+
     if (printer->name) {
 
         ret = RegOpenKeyW(hkeyPrinters, printer->name, &hkeyPrinter);
@@ -5385,9 +5387,13 @@ DWORD WINAPI GetPrinterDataExA(HANDLE hPrinter, LPCSTR pKeyName,
     ret = RegQueryValueExA(printer->name ? hkeySubkey : hkeyPrinters, pValueName,
                           0, pType, pData, pcbNeeded);
 
+    if (!ret && !pData) ret = ERROR_MORE_DATA;
+
     RegCloseKey(hkeySubkey);
     RegCloseKey(hkeyPrinter);
     RegCloseKey(hkeyPrinters);
+
+    TRACE("--> %d\n", ret);
     return ret;
 }
 
@@ -5411,6 +5417,8 @@ DWORD WINAPI GetPrinterDataExW(HANDLE hPrinter, LPCWSTR pKeyName,
     ret = RegOpenKeyW(HKEY_LOCAL_MACHINE, PrintersW, &hkeyPrinters);
     if (ret) return ret;
 
+    TRACE("printer->name: %s\n", debugstr_w(printer->name));
+
     if (printer->name) {
 
         ret = RegOpenKeyW(hkeyPrinters, printer->name, &hkeyPrinter);
@@ -5429,9 +5437,13 @@ DWORD WINAPI GetPrinterDataExW(HANDLE hPrinter, LPCWSTR pKeyName,
     ret = RegQueryValueExW(printer->name ? hkeySubkey : hkeyPrinters, pValueName,
                           0, pType, pData, pcbNeeded);
 
+    if (!ret && !pData) ret = ERROR_MORE_DATA;
+
     RegCloseKey(hkeySubkey);
     RegCloseKey(hkeyPrinter);
     RegCloseKey(hkeyPrinters);
+
+    TRACE("--> %d\n", ret);
     return ret;
 }
 

dlls/winspool.drv/tests/info.c

@@ -2364,6 +2364,14 @@ static void test_GetPrinterData(void)
     ok( !res && (type == REG_SZ) && ((needed == len) || (needed == (len * sizeof(WCHAR)))),
         "got %d, type %d, needed: %d and '%s' (expected ERROR_SUCCESS, REG_SZ and %d or %d)\n",
         res, type, needed, buffer, len, len * sizeof(WCHAR));
+
+    needed = 0xdeadbeef;
+    SetLastError(0xdeadbeef);
+    res = GetPrinterDataA(hprn, defaultspooldirectory, NULL, NULL, 0, &needed);
+    ok( (res == ERROR_MORE_DATA) && ((needed == len) || (needed == (len * sizeof(WCHAR)))),
+        "got %d, needed: %d (expected ERROR_MORE_DATA and %d or %d)\n",
+        res, needed, len, len * sizeof(WCHAR));
+
     /* ToDo: test SPLREG_*  */
 
     SetLastError(0xdeadbeef);
@@ -2451,6 +2459,13 @@ static void test_GetPrinterDataEx(void)
         "got %d, type %d, needed: %d and '%s' (expected ERROR_SUCCESS, REG_SZ and %d or %d)\n",
         res, type, needed, buffer, len, len * sizeof(WCHAR));
 
+    needed = 0xdeadbeef;
+    SetLastError(0xdeadbeef);
+    res = pGetPrinterDataExA(hprn, NULL, defaultspooldirectory, NULL, NULL, 0, &needed);
+    ok( (res == ERROR_MORE_DATA) && ((needed == len) || (needed == (len * sizeof(WCHAR)))),
+        "got %d, needed: %d (expected ERROR_MORE_DATA and %d or %d)\n",
+        res, needed, len, len * sizeof(WCHAR));
+
     SetLastError(0xdeadbeef);
     res = ClosePrinter(hprn);
     ok(res, "ClosePrinter error %d\n", GetLastError());