Hook CreateFile and CreateConsoleScreenBuffer

If console handles are created as GENERIC_WRITE, add GENERIC_READ in
order to be able to retrieve console information.  This fixes #93
(redirecting to CON).

ANSI.c

@@ -152,10 +152,11 @@
     remove wcstok, avoiding potential interference with the host;
     similarly, use a private heap instead of malloc.
 
-  v1.80, 26 to 28 October, 2017:
+  v1.80, 26 to 30 October, 2017:
     fix unloading;
     revert back to (re)storing buffer cursor position;
-    increase cache to five handles.
+    increase cache to five handles;
+    hook CreateFile & CreateConsoleScreenBuffer to enable readable handles.
 */
 
 #include "ansicon.h"
@@ -2286,6 +2287,62 @@ WINAPI My_lwrite( HFILE hFile, LPCSTR lpBuffer, UINT uBytes )
   return _lwrite( hFile, lpBuffer, uBytes );
 }
 
+
+//-----------------------------------------------------------------------------
+//   MyCreate...
+// Add GENERIC_READ access to enable retrieving console info.
+//-----------------------------------------------------------------------------
+
+HANDLE
+WINAPI MyCreateFileA( LPCSTR lpFileName, DWORD dwDesiredAccess,
+		      DWORD dwShareMode,
+		      LPSECURITY_ATTRIBUTES lpSecurityAttributes,
+		      DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes,
+		      HANDLE hTemplateFile )
+{
+  if (dwDesiredAccess == GENERIC_WRITE)
+  {
+    if (_stricmp( lpFileName, "con" ) == 0)
+      lpFileName = "CONOUT$";
+    if (_stricmp( lpFileName, "CONOUT$" ) == 0)
+      dwDesiredAccess |= GENERIC_READ;
+  }
+  return CreateFileA( lpFileName, dwDesiredAccess, dwShareMode,
+		      lpSecurityAttributes, dwCreationDisposition,
+		      dwFlagsAndAttributes, hTemplateFile );
+}
+
+HANDLE
+WINAPI MyCreateFileW( LPCWSTR lpFileName, DWORD dwDesiredAccess,
+		      DWORD dwShareMode,
+		      LPSECURITY_ATTRIBUTES lpSecurityAttributes,
+		      DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes,
+		      HANDLE hTemplateFile )
+{
+  if (dwDesiredAccess == GENERIC_WRITE)
+  {
+    if (_wcsicmp( lpFileName, L"con" ) == 0)
+      lpFileName = L"CONOUT$";
+    if (_wcsicmp( lpFileName, L"CONOUT$" ) == 0)
+      dwDesiredAccess |= GENERIC_READ;
+  }
+  return CreateFileW( lpFileName, dwDesiredAccess, dwShareMode,
+		      lpSecurityAttributes, dwCreationDisposition,
+		      dwFlagsAndAttributes, hTemplateFile );
+}
+
+HANDLE
+WINAPI MyCreateConsoleScreenBuffer( DWORD dwDesiredAccess, DWORD dwShareMode,
+				    const SECURITY_ATTRIBUTES* lpSecurityAttributes,
+				    DWORD dwFlags, LPVOID lpScreenBufferData )
+{
+  dwDesiredAccess |= GENERIC_READ;
+  return CreateConsoleScreenBuffer( dwDesiredAccess, dwShareMode,
+				    lpSecurityAttributes, dwFlags,
+				    lpScreenBufferData );
+}
+
+
 // ========== Environment variable
 
 void set_ansicon( PCONSOLE_SCREEN_BUFFER_INFO pcsbi )
@@ -2382,6 +2439,9 @@ HookFn Hooks[] = {
   { APIConsole, 	   "WriteConsoleW",             (PROC)MyWriteConsoleW,             NULL, NULL, NULL },
   { APIFile,		   "WriteFile",                 (PROC)MyWriteFile,                 NULL, NULL, NULL },
   { APIKernel,		   "_lwrite",                   (PROC)My_lwrite,                   NULL, NULL, NULL },
+  { APIFile,		   "CreateFileA",               (PROC)MyCreateFileA,               NULL, NULL, NULL },
+  { APIFile,		   "CreateFileW",               (PROC)MyCreateFileW,               NULL, NULL, NULL },
+  { APIKernel,		   "CreateConsoleScreenBuffer", (PROC)MyCreateConsoleScreenBuffer, NULL, NULL, NULL },
   { NULL, NULL, NULL, NULL, NULL, NULL }
 };
 

ansicon.c

@@ -90,7 +90,7 @@
     write newline with _putws, not putwchar (fixes redirecting to CON).
 */
 
-#define PDATE L"28 October, 2017"
+#define PDATE L"30 October, 2017"
 
 #include "ansicon.h"
 #include "version.h"

readme.txt

@@ -298,6 +298,8 @@ Version History
     1.80 - 28 October, 2017:
     - fix unloading;
     - fix -e et al when redirecting to CON;
+    - hook CreateFile and CreateConsoleScreenBuffer to force read/write access
+      (fixes redirecting to CON and Microsoft's conio);
     * go back to saving the buffer cursor position.
 
     1.72 - 24 December, 2015:
@@ -526,4 +528,4 @@ Distribution
 
 
 =============================
-Jason Hood, 28 October, 2017.
+Jason Hood, 30 October, 2017.