Adjust to use 1-based, note in API

src/browser/Linkifier.ts

@@ -306,7 +306,9 @@ export class Linkifier implements ILinkifier {
       e => {
         this._onLinkTooltip.fire(this._createLinkHoverEvent(x1, y1, x2, y2, fg));
         if (matcher.hoverTooltipCallback) {
-          matcher.hoverTooltipCallback(e, uri, { start: { row: y1, col: x1 }, end: { row: y2, col: x2 } });
+          // Note that IViewportRange use 1-based coordinates to align with escape sequences such
+          // as CUP which use 1,1 as the default for row/col
+          matcher.hoverTooltipCallback(e, uri, { start: { row: y1 + 1, col: x1 + 1 }, end: { row: y2 + 1, col: x2 } });
         }
       },
       () => {

typings/xterm.d.ts

@@ -862,12 +862,12 @@ declare module 'xterm' {
    */
   interface IViewportCellPosition {
     /**
-     * The column of the cell.
+     * The column of the cell. Note that this is 1-based; the first column is column 1.
      */
     col: number;
 
     /**
-     * The row of the cell.
+     * The row of the cell. Note that this is 1-based; the first row is row 1.
      */
     row: number;
   }