Konsole: Add support for ECMA-48 REP: repeating previous character

Patch by btown using lxde/qtermwidget@60221da by @yan12125

ECMA-48 8.3.103 describes the sequence CSI Pn b for repeating the
previous character in the data stream. This sequence has been present
in XTerm since January 1997 and has been added to the latest terminfo
entry for xterm-new and derived entries such as xterm-256color.

https://phabricator.kde.org/D10064

Taken from KDE patches and adapted to TDE.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

konsole/konsole/TEScreen.cpp

@@ -81,7 +81,8 @@ TEScreen::TEScreen(int l, int c)
     ef_fg(cacol()), ef_bg(cacol()), ef_re(0),
     sa_cuX(0), sa_cuY(0),
     sa_cu_re(0), sa_cu_fg(cacol()), sa_cu_bg(cacol()),
-    lastPos(-1)
+    lastPos(-1),
+    lastDrawnChar(0)
 {
   /*
     this->lines   = lines;
@@ -300,6 +301,26 @@ void TEScreen::insertChars(int n)
   clearImage(loc(cuX,cuY),loc(q-1,cuY),' ');
 }
 
+void TEScreen::repeatChars(int n)
+{
+    if (n == 0)
+    {
+        n = 1; // Default
+    }
+
+    // From ECMA-48 version 5, section 8.3.103:
+    // "If the character preceding REP is a control function or part of a
+    // control function, the effect of REP is not defined by this Standard."
+    //
+    // So, a "normal" program should always use REP immediately after a visible
+    // character (those other than escape sequences). So, lastDrawnChar can be
+    // safely used.
+    for (int i = 0; i < n; i++)
+    {
+        ShowCharacter(lastDrawnChar);
+    }
+}
+
 /*! delete `n' lines starting from (including) the cursor position.
 
     The cursor is not moved by the operation.
@@ -762,6 +783,8 @@ void TEScreen::ShowCharacter(unsigned short c)
   
   lastPos = i;
 
+  lastDrawnChar = c;
+
   cuX += w--;
 
   while(w)

konsole/konsole/TEScreen.h

@@ -83,6 +83,7 @@ public: // these are all `Screen' operations
     void eraseChars  (int n);
     void deleteChars (int n);
     void insertChars (int n);
+    void repeatChars (int n);
     void deleteLines (int n);
     void insertLines (int n);
     //
@@ -271,6 +272,9 @@ private: // helper
     // last position where we added a character
     int lastPos;
 
+    // used in REP (repeating char)
+    unsigned short lastDrawnChar;
+
     // modes
 
     ScreenParm saveParm;

konsole/konsole/TEmuVt102.cpp

@@ -267,7 +267,7 @@ void TEmuVt102::initTokenizer()
   for(i =  0;                      i < 256; i++) tbl[ i]  = 0;
   for(i =  0;                      i <  32; i++) tbl[ i] |= CTL;
   for(i = 32;                      i < 256; i++) tbl[ i] |= CHR;
-  for(s = (UINT8*)"@ABCDGHILMPSTXZcdfry"; *s; s++) tbl[*s] |= CPN;
+  for(s = (UINT8*)"@ABCDGHILMPSTXZbcdfry"; *s; s++) tbl[*s] |= CPN;
 // resize = \e[8;<row>;<col>t
   for(s = (UINT8*)"t"; *s; s++) tbl[*s] |= CPS;
   for(s = (UINT8*)"0123456789"        ; *s; s++) tbl[*s] |= DIG;
@@ -631,6 +631,7 @@ switch( N )
     case TY_CSI_PN('T'      ) : scr->scrollDown           (p         ); break;
     case TY_CSI_PN('X'      ) : scr->eraseChars           (p         ); break;
     case TY_CSI_PN('Z'      ) : scr->backTabulate         (p         ); break;
+    case TY_CSI_PN('b'      ) : scr->repeatChars          (p         ); break;
     case TY_CSI_PN('c'      ) :      reportTerminalType   (          ); break; //VT100
     case TY_CSI_PN('d'      ) : scr->setCursorY           (p         ); break; //LINUX
     case TY_CSI_PN('f'      ) : scr->setCursorYX          (p,       q); break; //VT100