Improces TrimmedLineLength a bit

Removed cache (was invalid when the optional cols parameter was used)
Imply that the last cell index + 1 is the length (+ double width specialty)
Use the cols parameter for Reflow wider as we can be sure in that situation that we don't have special long lines (changes aren't aggregated as we merge line)

lib/buffer/buffer_line.dart

@@ -45,7 +45,6 @@ class BufferLine {
   bool isWrapped;
 
   int _maxCols = 64;
-  int? _currentTrimmedLength;
 
   void ensure(int length) {
     if (length <= _maxCols) {
@@ -79,7 +78,6 @@ class BufferLine {
     for (var i = moveEnd; i < bufferEnd; i++) {
       cells[i] = 0x00;
     }
-    _currentTrimmedLength = null;
   }
 
   void insertN(int index, int count) {
@@ -109,7 +107,6 @@ class BufferLine {
     for (var i = moveStart; i < moveStart + moveOffset; i++) {
       cells[i] = 0x00;
     }
-    _currentTrimmedLength = null;
   }
 
   void clear() {
@@ -129,7 +126,6 @@ class BufferLine {
   void cellClear(int index) {
     _cells.setInt64(index * _cellSize, 0x00);
     _cells.setInt64(index * _cellSize + 8, 0x00);
-    _currentTrimmedLength = null;
   }
 
   void cellInitialize(
@@ -144,7 +140,6 @@ class BufferLine {
     _cells.setInt32(cell + _cellBgColor, cursor.bg);
     _cells.setInt8(cell + _cellWidth, width);
     _cells.setInt8(cell + _cellFlags, cursor.flags);
-    _currentTrimmedLength = null;
   }
 
   bool cellHasContent(int index) {
@@ -157,7 +152,6 @@ class BufferLine {
 
   void cellSetContent(int index, int content) {
     _cells.setInt32(index * _cellSize + _cellContent, content);
-    _currentTrimmedLength = null;
   }
 
   int cellGetFgColor(int index) {
@@ -202,7 +196,6 @@ class BufferLine {
 
   void cellSetWidth(int index, int width) {
     _cells.setInt8(index * _cellSize + _cellWidth, width);
-    _currentTrimmedLength = null;
   }
 
   void cellClearFlags(int index) {
@@ -226,27 +219,22 @@ class BufferLine {
     cellSetBgColor(index, cursor.bg);
     cellSetFlags(index, cursor.flags);
     cellSetWidth(index, 0);
-    _currentTrimmedLength = null;
   }
 
   int getTrimmedLength([int? cols]) {
-    if (_currentTrimmedLength != null) {
-      return _currentTrimmedLength!;
-    }
     if (cols == null) {
       cols = _maxCols;
     }
     for (var i = cols - 1; i >= 0; i--) {
       if (cellGetContent(i) != 0) {
-        var length = 0;
-        for (var j = 0; j <= i; j++) {
-          length += cellGetWidth(j);
-        }
-        _currentTrimmedLength = length;
-        return length;
+        // we are at the last cell in this line that has content.
+        // the length of this line is the index of this cell + 1
+        // the only exception is that if that last cell is wider
+        // than 1 then we have to add the diff
+        final lastCellWidth = cellGetWidth(i);
+        return i + lastCellWidth;
       }
     }
-    _currentTrimmedLength = 0;
     return 0;
   }
 
@@ -262,7 +250,6 @@ class BufferLine {
     for (var i = 0; i < intsToCopy; i++) {
       cells[dstStart + i] = srcCells[srcStart + i];
     }
-    _currentTrimmedLength = null;
   }
 
   // int cellGetHash(int index) {

lib/buffer/reflow_strategy_wider.dart

@@ -17,7 +17,9 @@ class ReflowStrategyWider extends ReflowStrategy {
         if (!nextLine.isWrapped) {
           break;
         }
-        final lineLength = line.getTrimmedLength();
+        // when we are reflowing wider we can be sure that this line and the next all have equal to or less than
+        // 'newCols' length => we can pass newCols as the upper limit
+        final lineLength = line.getTrimmedLength(newCols);
 
         var copyDestIndex = lineLength;
         if (copyDestIndex >= 1 &&
@@ -32,7 +34,9 @@ class ReflowStrategyWider extends ReflowStrategy {
           // no more space to unwrap
           break;
         }
-        final nextLineLength = nextLine.getTrimmedLength();
+        // when we are reflowing wider we can be sure that this line and the next all have equal to or less than
+        // 'newCols' length => we can pass newCols as the upper limit
+        final nextLineLength = nextLine.getTrimmedLength(newCols);
         var moveCount = min(spaceOnLine, nextLineLength);
         if (moveCount <= 0) {
           break;