diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index addbe66a..0ac4be4e 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -471,11 +471,25 @@ var EditSession = function(text, mode) {
             var longestScreenLine = 0;
 
             for ( var i = 0; i < lines.length; i++) {
-                var line = lines[i],
-                    len = line.length,
-                    screenLen = this.$getStringScreenWidth(line)[0];
+                var foldLine = this.getFoldLine(i),
+                    line, len;
+
+                line = lines[i];
+                if (foldLine) {
+                    var end = foldLine.range.end;
+                    line = this.getFoldDisplayLine(foldLine, end.row, line.length);
+                    // Continue after the foldLine.end.row. All the lines in
+                    // between are folded.
+                    i = end.row;
+                }
+                len = line.length;
                 longestLine = Math.max(longestLine, len);
-                longestScreenLine = Math.max(longestScreenLine, screenLen);
+                if (!this.$useWrapMode) {
+                    longestScreenLine = Math.max(
+                        longestScreenLine,
+                        this.$getStringScreenWidth(line)[0]
+                    );
+                }
             }
             this.width = longestLine;
 
@@ -875,7 +889,7 @@ var EditSession = function(text, mode) {
             start = e.data.range.start,
             end = e.data.range.end;
 
-        console.log("onChange", action, e.data.range + "");
+//        console.log("onChange", action, e.data.range + "");
 
         if (action.indexOf("Lines") != -1) {
             if (action == "insertLines") {
@@ -1147,34 +1161,16 @@ var EditSession = function(text, mode) {
         return this.getRowLength(row) * config.lineHeight;
     }
 
-    this.getScreenLastRowColumn = function(screenRow, returnDocPosition) {
-        if (!this.$useWrapMode) {
-            return this.$getStringScreenWidth(this.getLine(screenRow))[0];
-        }
-
-        var rowData = this.$screenToDocumentRow(screenRow);
-        var docRow = rowData[0],
-            row = rowData[1];
-
-        var start, end;
-        if (this.$wrapData[docRow][row]) {
-            start = (this.$wrapData[docRow][row - 1] || 0);
-            end = this.$wrapData[docRow][row];
-            returnDocPosition && end--;
-        } else {
-            end = this.getLine(docRow).length;
-            start = (this.$wrapData[docRow][row - 1] || 0);
-        }
-        if (!returnDocPosition) {
-            return this.$getStringScreenWidth(this.getLine(docRow).substring(start, end))[0];
-        } else {
-            return end;
-        }
+    this.getScreenLastRowColumn = function(screenRow) {
+        // Note: This won't work if someone has more then
+        // 1.7976931348623158e+307 characters in one row. But I think we can
+        // live with this limitation ;)
+        return this.screenToDocumentColumn(screenRow, Number.MAX_VALUE / 10)
     };
 
     this.getDocumentLastRowColumn = function(docRow, docColumn) {
         var screenRow = this.documentToScreenRow(docRow, docColumn);
-        return this.getScreenLastRowColumn(screenRow, true);
+        return this.getScreenLastRowColumn(screenRow);
     }
 
     this.getRowSplitData = function(row) {
@@ -1201,7 +1197,7 @@ var EditSession = function(text, mode) {
             foldLineRowLength;
 
         var row = 0,
-            rowLength;
+            rowLength = 0;
 
         while (row <= screenRow) {
             foldLine = this.getFoldLine(docRow, lastFoldLine);
@@ -1209,7 +1205,7 @@ var EditSession = function(text, mode) {
                 lastFoldLine = foldLine;
                 rowLength = foldLine.getRowLength();
             } else {
-                rowLength = this.getRowLength(row);
+                rowLength = this.getRowLength(docRow);
             }
             if (row + rowLength - 1 >= screenRow) {
                 break;
@@ -1294,6 +1290,17 @@ var EditSession = function(text, mode) {
     };
 
     this.doc2Screen = function(docRow, docColumn) {
+        var wrapData;
+        if (this.$useWrapMode) {
+            wrapData = this.$wrapData;
+            if (docRow > wrapData.length - 1) {
+                return [
+                    this.getScreenLength(),
+                    wrapData.length == 0 ? 0 : (wrapData[wrapData.length - 1].length - 1)
+                ];
+            }
+        }
+
         var screenRow = 0,
             screenColumn = 0,
             foldStartRow = null,
@@ -1331,30 +1338,19 @@ var EditSession = function(text, mode) {
             textLine = this.getLine(docRow).substring(0, docColumn);
             foldStartRow = docRow;
         } else {
-            // Build the textline using the FoldLine walker.
-            var line;
-            foldLine.walk(function(placeholder, row, column, lastColumn, isNewRow) {
-                if (placeholder) {
-                    textLine += placeholder;
-                } else {
-                    if (isNewRow) {
-                        line = this.getLine(row);
-                    }
-                    textLine += line.substring(lastColumn, column);
-                }
-            }.bind(this), docRow, docColumn)
+            textLine = this.getFoldDisplayLine(foldLine, docRow, docColumn);
         }
 
         // Clamp textLine if in wrapMode.
         if (this.$useWrapMode) {
-            var wrapData = this.$wrapData[foldStartRow];
+            var wrapRow = wrapData[foldStartRow];
             var screenRowOffset = 0;
-            while (docColumn >= wrapData[screenRowOffset]) {
+            while (docColumn >= wrapRow[screenRowOffset]) {
                 screenRow ++;
                 screenRowOffset++;
             }
             textLine = textLine.substring(
-                wrapData[screenRowOffset - 1] || 0,  textLine.length);
+                wrapRow[screenRowOffset - 1] || 0,  textLine.length);
         }
 
         return [screenRow, this.$getStringScreenWidth(textLine)[0], textLine];
@@ -1868,10 +1864,9 @@ var EditSession = function(text, mode) {
         }
 
         // TODO: Recalculate wrapData
-        // TODO: Recalculate width etc.
-        // TODO: Mark as dirty etc.
 
         // Notify that fold data has changed.
+        this.$modified = true;
         this._dispatchEvent("changeFold");
     };
 
@@ -1917,6 +1912,7 @@ var EditSession = function(text, mode) {
         // TODO: Update wrapData.
 
         // Notify that fold data has changed.
+        this.$modified = true;
         this._dispatchEvent("changeFold");
     }
 
@@ -1932,6 +1928,7 @@ var EditSession = function(text, mode) {
         cloneFolds.forEach(function(fold) {
             this.removeFold(fold);
         }, this);
+        this.$modified = true;
     }
 
     /**
@@ -1949,6 +1946,24 @@ var EditSession = function(text, mode) {
                     : docRow)
     };
 
+    this.getFoldDisplayLine = function(foldLine, endRow, endColumn) {
+        // Build the textline using the FoldLine walker.
+        var line = "",
+            textLine = "";
+
+        foldLine.walk(function(placeholder, row, column, lastColumn, isNewRow) {
+            if (placeholder) {
+                textLine += placeholder;
+            } else {
+                if (isNewRow) {
+                    line = this.getLine(row);
+                }
+                textLine += line.substring(lastColumn, column);
+            }
+        }.bind(this), endRow, endColumn);
+        return textLine;
+    }
+
 }).call(EditSession.prototype);
 
 exports.EditSession = EditSession;