Documentation for values in EDITSTREAM es.dwError?   

Does anyone know where the error return values for the EM_STREAMIN message 
might be documented? Here's a snippet of code from an application which uses 
EM_STREAMIN to load an RTF file:

/* condition sf_flags for insert */
DWORD dwFlags = SF_RTF | SFF_SELECTION;

/* Initialize EDITSTREAM structure */
EDITSTREAM es;
ZeroMemory ((PVOID) &es, sizeof (EDITSTREAM));
es.dwCookie = (DWORD) hFile; // Send hFile to callback function
es.dwError = 0;
es.pfnCallback = ReadScriptCallback;

/* shut off notification messages during read */
DWORD dwOldEventMask = (DWORD) SendMessage (hwndRe, EM_SETEVENTMASK, 0, 
(LPARAM) 0);

/* stream in text */
DWORD dwRetv = (DWORD) SendMessage (hwndRe, EM_STREAMIN, (WPARAM) dwFlags, 
(LPARAM) &es);

/* store GetLastError() before calling anything else that might reset erret */
DWORD dwLocalErret = GetLastError ();

/* Close the file */
CloseHandle (hFile);

/* Reset EVENTMASK to its previous value */
SendMessage (hwndRe, EM_SETEVENTMASK, 0, (LPARAM) dwOldEventMask);

/* attempt to detect errors from EM_STREAMIN */
if (dwRetv == 0 || es.dwError != 0)
  {
  *erret = TNR_FILE_ERROR_OPSYSERR;
  /* This is an error logging function */
  MIMessageDisplay (EPF_ERR, TEXT("(Line %d: Error %08X) system error = %d, 
es.dwError  = %d, streaming in %s"), 
__LINE__, *erret, dwLocalErret, es.dwError, fname);
  return FALSE;
  }
*erret = TNR_FILE_ERROR_NONE;
return TRUE;

// end of code snippet
This snippet is from an application which has loaded in the neighborhood of 
tens of thousands of files during its life on the market -- normally, it 
works fine. However, a recent script submitted by one of our customers causes 
an unusual error return from the EM_STREAMIN message. The file's content 
language is Dhivehi and as far as I can determine, the file is read 
successfully.

According to Microsoft "documentation", 
1. The return from SendMessage (hwndRe, EM_STREAMIN...) is "This message 
returns the number of characters read." In this example, the return value is 
0x3F1. 

2. On return, es.dwError == 0xfffffffa (-6) . According to documentation:

"a value of zero indicates no error. A nonzero value can be the return 
value of the EditStreamCallback function or a code indicating that the 
control encountered an error."

The only possible return from our callback function is 0. This value (-6) 
seems to have been set by the operating system and seems to indicate that an 
error occurred in streaming.

However, the errors are undocumented, at least as far as I can tell.

Though I can ignore this error and continue, it seems a little chancy to 
assume the resultant rich edit control is properly formatted.

Any assistance in documenting the return values would be appreciated. 

Thanks!!!

date: Thu, 7 Aug 2008 11:28:01 -0700   author:   AustinJstrings