vi: reduce amount of memset'ing on each screen refresh

diff --git a/editors/vi.c b/editors/vi.c
index 65a82b1382337f542c92c6fefcf011e02d94f312..f06cad22703917be020cc215a2b9227ebfc6058e 100644 (file)
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2516,9 +2516,9 @@ static void place_cursor(int row, int col, int optimize)
                }
  skip: ;
        }
+       last_row = row;
 #endif /* FEATURE_VI_OPTIMIZE_CURSOR */
        write1(cm);
-       last_row = row;
 }
 
 //----- Erase from cursor to end of line -----------------------
@@ -2762,10 +2762,9 @@ static char* format_line(char *src, int li)
        int ofs = offset;
        char *dest = scr_out_buf; // [MAX_SCR_COLS + MAX_TABSTOP * 2]
 
-       memset(dest, ' ', MAX_SCR_COLS + MAX_TABSTOP * 2);
-
        c = '~'; // char in col 0 in non-existent lines is '~'
-       for (co = 0; co < columns + MAX_TABSTOP; co++) {
+       co = 0;
+       while (co < columns + tabstop) {
                // have we gone past the end?
                if (src < end) {
                        c = *src++;
@@ -2790,11 +2789,11 @@ static char* format_line(char *src, int li)
                                }
                        }
                }
-               dest[co] = c;
+               dest[co++] = c;
                // discard scrolled-off-to-the-left portion,
                // in tabstop-sized pieces
                if (ofs >= tabstop && co >= tabstop) {
-                       memmove(dest, dest + tabstop, co + 1);
+                       memmove(dest, dest + tabstop, co);
                        co -= tabstop;
                        ofs -= tabstop;
                }
@@ -2803,9 +2802,14 @@ static char* format_line(char *src, int li)
        }
        // check "short line, gigantic offset" case
        if (co < ofs)
-               ofs = co + 1;
-       dest[ofs + MAX_SCR_COLS] = '\0';
-       return &dest[ofs];
+               ofs = co;
+       // discard last scrolled off part
+       co -= ofs;
+       dest += ofs;
+       // fill the rest with spaces
+       if (co < columns)
+               memset(&dest[co], ' ', columns - co);
+       return dest;
 }
 
 //----- Refresh the changed screen lines -----------------------