From 9fbe42a583fadbc781168feaec9762f1d74620ff Mon Sep 17 00:00:00 2001
From: Jason Hood <jadoxa@yahoo.com.au>
Date: Fri, 24 Nov 2017 11:10:42 +1000
Subject: [PATCH] Escape control characters; fix CRM issues

Since ESC is now preserved for unrecognised sequences, I feel able to
use it to escape control characters in order to display them (e.g.
"\e\e" will display a single escape).

Control mode would not display the recognised controls (i.e. BEL, SO and
SI) and would not work if it was turned off in the same string.
---
 ANSI.c     | 43 ++++++++++++++++++++++++++++++++-----------
 ansicon.c  |  2 +-
 readme.txt | 10 +++++++---
 3 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/ANSI.c b/ANSI.c
index 3b08d5d..e0ce4a7 100644
--- a/ANSI.c
+++ b/ANSI.c
@@ -162,7 +162,8 @@
     fix escape followed by CRM in control mode;
     use the system default sound for the bell;
     add DECPS Play Sound;
-    use intermediate byte '+' to use buffer, not window.
+    use intermediate byte '+' to use buffer, not window;
+    ESC followed by a control character will display that character.
 */
 
 #include "ansicon.h"
@@ -185,7 +186,7 @@ HANDLE	hHeap;			// local memory heap
 HANDLE	hBell;
 
 #define CACHE	5
-struct
+struct Cache
 {
   HANDLE h;
   DWORD  mode;
@@ -478,11 +479,9 @@ void FlushBuffer( void )
 
   if (pState->crm)
   {
-    DWORD mode;
-    GetConsoleMode( hConOut, &mode );
-    SetConsoleMode( hConOut, mode & ~ENABLE_PROCESSED_OUTPUT );
+    SetConsoleMode( hConOut, cache[0].mode & ~ENABLE_PROCESSED_OUTPUT );
     WriteConsole( hConOut, ChBuffer, nCharInBuffer, &nWritten, NULL );
-    SetConsoleMode( hConOut, mode );
+    SetConsoleMode( hConOut, cache[0].mode );
   }
   else
   {
@@ -699,9 +698,11 @@ void InterpretEscSeq( void )
 	return;
 
 	case 7:
-	  mode = ENABLE_PROCESSED_OUTPUT;
+	  mode = cache[0].mode;
 	  if (suffix == 'h')
 	    mode |= ENABLE_WRAP_AT_EOL_OUTPUT;
+	  else
+	    mode &= ~ENABLE_WRAP_AT_EOL_OUTPUT;
 	  SetConsoleMode( hConOut, mode );
 	return;
       }
@@ -1269,6 +1270,7 @@ ParseAndPrintString( HANDLE hDev,
 	get_state();
 	state = (pState->crm) ? 7 : 2;
       }
+      else if (pState->crm) PushBuffer( (WCHAR)c );
       else if (c == BEL)
       {
 	if (hBell == NULL)
@@ -1280,8 +1282,15 @@ ParseAndPrintString( HANDLE hDev,
     }
     else if (state == 2)
     {
-      if (c == ESC)
-	PushBuffer( ESC );
+      if (c < '\x20')
+      {
+	FlushBuffer();
+	pState->crm = TRUE;
+	PushBuffer( (WCHAR)c );
+	FlushBuffer();
+	pState->crm = FALSE;
+	state = 1;
+      }
       else if (c >= '\x20' && c <= '\x2f')
 	suffix2 = c;
       else if (suffix2 != 0)
@@ -1433,7 +1442,11 @@ ParseAndPrintString( HANDLE hDev,
     }
     else if (state == 9)
     {
-      if (c == 'l') pState->crm = FALSE;
+      if (c == 'l')
+      {
+	FlushBuffer();
+	pState->crm = FALSE;
+      }
       else
       {
 	PushBuffer( ESC );
@@ -2098,7 +2111,15 @@ BOOL IsConsoleHandle( HANDLE h )
 
   for (c = 0; c < CACHE; ++c)
     if (cache[c].h == h)
-      return (cache[c].mode & ENABLE_PROCESSED_OUTPUT);
+    {
+      if (c != 0)
+      {
+	struct Cache tc = cache[c];
+	do cache[c] = cache[c-1]; while (--c > 0);
+	cache[0] = tc;
+      }
+      return (cache[0].mode & ENABLE_PROCESSED_OUTPUT);
+    }
 
   while (--c > 0)
     cache[c] = cache[c-1];
diff --git a/ansicon.c b/ansicon.c
index ff2b1ac..9f3ba74 100644
--- a/ansicon.c
+++ b/ansicon.c
@@ -90,7 +90,7 @@
     write newline with _putws, not putwchar (fixes redirecting to CON).
 */
 
-#define PDATE L"23 November, 2017"
+#define PDATE L"24 November, 2017"
 
 #include "ansicon.h"
 #include "version.h"
diff --git a/readme.txt b/readme.txt
index 00b4741..5fe8603 100644
--- a/readme.txt
+++ b/readme.txt
@@ -198,6 +198,9 @@ Sequences Recognised
     and underline will set the background intensity; conceal uses background as
     foreground.  See "sequences.txt" for a more complete description.
 
+    Escape followed by a control character will display that character, not
+    perform its function.  An unrecognised sequence will preserve the escape.
+
     I make a distinction between '\e[m' and '\e[0;...m'.  Both will restore the
     original foreground/background colors (and so '0' should be the first para-
     meter); the former will also restore the original bold and underline attri-
@@ -295,15 +298,16 @@ Version History
 
     Legend: + added, - bug-fixed, * changed.
 
-    1.80 - 23 November, 2017:
+    1.80 - 24 November, 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);
     - fix cursor report with duplicated digits (e.g. "11" was only writing "1");
-    - fix escape followed by CRM in control mode;
+    - fix issues with CRM;
     * go back to saving the buffer cursor position;
     * preserve escape that isn't part of a sequence;
+    * escape control characters;
     + use the system default sound for the bell;
     + added Play Sound DECPS;
     + added '+' intermediate byte to use the buffer, rather than the window.
@@ -535,4 +539,4 @@ Distribution
 
 
 =============================
-Jason Hood, 23 November, 2017.
+Jason Hood, 24 November, 2017.