negative pt in runeAt is weird

.vscode/launch.json

@@ -0,0 +1,22 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Attach to Process",
+            "type": "go",
+            "request": "attach",
+            "mode": "local",
+            "processId": 0
+        },
+        {
+            "name": "Launch file",
+            "type": "go",
+            "request": "launch",
+            "mode": "debug",
+            "program": "${file}"
+        }
+    ]
+}

buffer.go

@@ -64,13 +64,15 @@ func (bp *Buffer) getText() string {
 	return string(ret)
 }
 
-// RuneAt finally reliable!!
+// RuneAt finally reliable!! (well, maybe not)
 func (bp *Buffer) RuneAt(pt int) (rune, error) {
+	log.Println("RuneAt pt = ", pt)
 	if pt >= len(bp.data) {
 		return 0, errors.New("beyond data buffer in RuneAt")
 	}
 	if pt < 0 {
-		return '\u0000', errors.New("negative buffer pointer in RuneAt")
+		//return '\u0000', errors.New("negative buffer pointer in RuneAt")
+		pt = 0
 	}
 	if npt := bp.dataPointForBufferPoint(pt); npt < len(bp.data) {
 		return bp.data[npt], nil
@@ -325,7 +327,6 @@ func (bp *Buffer) ColumnForPoint(point int) (column int) {
 		point = bp.TextSize - 1
 	}
 	return point - bp.LineStart(point) + 1
-
 }
 
 // XYForPoint returns the cursor location for a pt in the buffer

command.go

@@ -21,7 +21,6 @@ func (e *Editor) up() {
 }
 func (e *Editor) down() {
 	e.CurrentBuffer.PointDown()
-
 }
 func (e *Editor) lnbegin() {
 	e.CurrentBuffer.SetPoint(e.CurrentBuffer.LineStart(e.CurrentBuffer.Point))
@@ -143,7 +142,7 @@ func (e *Editor) gotoline() {
 func (e *Editor) insertfile() {
 	fname := e.getInput("Insert file: ")
 	if fname != "" {
-		res := e.InsertFile(fname, false)
+		res := e.InsertFile(fname, true)
 		if res {
 			e.msg("Loaded file %s", fname)
 		}

files.go

@@ -47,9 +47,9 @@ func (e *Editor) Save(fname string) bool {
 }
 
 // LoadFile foo
-func (e *Editor) LoadFile(fname string) bool {
-	return false
-}
+// func (e *Editor) LoadFile(fname string) bool {
+// 	return false
+// }
 
 // InsertFile reads file into buffer at point
 func (e *Editor) InsertFile(fname string, modflag bool) bool {
@@ -58,12 +58,13 @@ func (e *Editor) InsertFile(fname string, modflag bool) bool {
 	if err != nil {
 		e.msg("Failed to read and insert file \"%s\".", fname)
 	}
-	if modflag == true {
+	if !modflag { // just do a load into buffer with no modification
 		bp.setText(string(dat))
-	} else {
+		bp.modified = false
+	} else { // insert into buffer and mark as modified.
 		bp.Insert(string(dat))
+		bp.modified = true
 	}
-	bp.modified = true
 	e.msg("File \"%s\" %d bytes read.", fname, len(dat))
 	return true
 }