Merge remote-tracking branch 'official/master' into per-axis-grid

Conflicts:
	tests/two-axes.html

diff --combined auto_tests/misc/local.html
index de1d483,fb99a26..1604e8e
--- 1/auto_tests/misc/local.html
--- 2/auto_tests/misc/local.html
+++ b/auto_tests/misc/local.html
@@@ -23,13 -23,13 +23,14 @@@
    <script type="text/javascript" src="../tests/axis_labels.js"></script>
    <script type="text/javascript" src="../tests/axis_labels-deprecated.js"></script>
    <script type="text/javascript" src="../tests/callback.js"></script>
+   <script type="text/javascript" src="../tests/connect_separated_points.js"></script>
    <script type="text/javascript" src="../tests/css.js"></script>
    <script type="text/javascript" src="../tests/custom_bars.js"></script>
    <script type="text/javascript" src="../tests/date_formats.js"></script>
    <script type="text/javascript" src="../tests/dygraph-options-tests.js"></script>
    <script type="text/javascript" src="../tests/error_bars.js"></script>
    <script type="text/javascript" src="../tests/formats.js"></script>
 +  <script type="text/javascript" src="../tests/grid_per_axis.js"></script>
    <script type="text/javascript" src="../tests/interaction_model.js"></script>
    <script type="text/javascript" src="../tests/missing_points.js"></script>
    <script type="text/javascript" src="../tests/multi_csv.js"></script>

diff --combined dygraph.js
index 82725d5,44214ad..5e4ba62
--- 1/dygraph.js
--- 2/dygraph.js
+++ b/dygraph.js
@@@ -344,24 -344,18 +344,24 @@@ Dygraph.DEFAULT_ATTRS = 
        pixelsPerLabel: 60,
        axisLabelFormatter: Dygraph.dateAxisFormatter,
        valueFormatter: Dygraph.dateString_,
 +      drawGrid: true,
 +      independentTicks: true,
        ticker: null  // will be set in dygraph-tickers.js
      },
      y: {
        pixelsPerLabel: 30,
        valueFormatter: Dygraph.numberValueFormatter,
        axisLabelFormatter: Dygraph.numberAxisLabelFormatter,
 +      drawGrid: true,
 +      independentTicks: true,
        ticker: null  // will be set in dygraph-tickers.js
      },
      y2: {
        pixelsPerLabel: 30,
        valueFormatter: Dygraph.numberValueFormatter,
        axisLabelFormatter: Dygraph.numberAxisLabelFormatter,
 +      drawGrid: false,
 +      independentTicks: false,
        ticker: null  // will be set in dygraph-tickers.js
      }
    }
@@@ -2284,6 -2278,17 +2284,17 @@@ Dygraph.prototype.gatherDatasets_ = fun
    var datasets = [];
    var extremes = {};  // series name -> [low, high]
    var i, j, k;
+   var errorBars = this.attr_("errorBars");
+   var customBars = this.attr_("customBars");
+   var bars = errorBars || customBars;
+   var isValueNull = function(sample) {
+     if (!bars) {
+       return sample[1] === null;
+     } else {
+       return customBars ? sample[1][1] === null : 
+         errorBars ? sample[1][0] === null : false;
+     }
+   };
  
    // Loop over the fields (series).  Go from the last to the first,
    // because if they're stacked that's how we accumulate the values.
@@@ -2302,11 -2307,11 +2313,11 @@@
      // Prune down to the desired range, if necessary (for zooming)
      // Because there can be lines going to points outside of the visible area,
      // we actually prune to visible points, plus one on either side.
-     var bars = this.attr_("errorBars") || this.attr_("customBars");
      if (dateWindow) {
        var low = dateWindow[0];
        var high = dateWindow[1];
        var pruned = [];
+ 
        // TODO(danvk): do binary search instead of linear search.
        // TODO(danvk): pass firstIdx and lastIdx directly to the renderer.
        var firstIdx = null, lastIdx = null;
@@@ -2318,14 -2323,36 +2329,36 @@@
            lastIdx = k;
          }
        }
+ 
        if (firstIdx === null) firstIdx = 0;
-       if (firstIdx > 0) firstIdx--;
+       var correctedFirstIdx = firstIdx;
+       var isInvalidValue = true;
+       while (isInvalidValue && correctedFirstIdx > 0) {
+         correctedFirstIdx--;
+         isInvalidValue = isValueNull(series[correctedFirstIdx]);
+       }
+ 
        if (lastIdx === null) lastIdx = series.length - 1;
-       if (lastIdx < series.length - 1) lastIdx++;
-       boundaryIds[i-1] = [firstIdx, lastIdx];
+       var correctedLastIdx = lastIdx;
+       isInvalidValue = true;
+       while (isInvalidValue && correctedLastIdx < series.length - 1) {
+         correctedLastIdx++;
+         isInvalidValue = isValueNull(series[correctedLastIdx]);
+       }
+ 
+       boundaryIds[i-1] = [(firstIdx > 0) ? firstIdx - 1 : firstIdx, 
+           (lastIdx < series.length - 1) ? lastIdx + 1 : lastIdx];
+ 
+       if (correctedFirstIdx!==firstIdx) {
+         pruned.push(series[correctedFirstIdx]);
+       }
        for (k = firstIdx; k <= lastIdx; k++) {
          pruned.push(series[k]);
        }
+       if (correctedLastIdx !== lastIdx) {
+         pruned.push(series[correctedLastIdx]);
+       }
+ 
        series = pruned;
      } else {
        boundaryIds[i-1] = [0, series.length-1];
@@@ -2594,15 -2621,12 +2627,15 @@@ Dygraph.prototype.computeYAxisRanges_ 
    };
    var numAxes = this.attributes_.numAxes();
    var ypadCompat, span, series, ypad;
 +  
 +  var p_axis;
  
    // Compute extreme values, a span and tick marks for each axis.
    for (var i = 0; i < numAxes; i++) {
      var axis = this.axes_[i];
      var logscale = this.attributes_.getForAxis("logscale", i);
      var includeZero = this.attributes_.getForAxis("includeZero", i);
 +    var independentTicks = this.attributes_.getForAxis("independentTicks", i);
      series = this.attributes_.seriesForAxis(i);
  
      // Add some padding. This supports two Y padding operation modes:
@@@ -2720,33 -2744,20 +2753,33 @@@
      } else {
        axis.computedValueRange = axis.extremeRange;
      }
 -
 -    // Add ticks. By default, all axes inherit the tick positions of the
 -    // primary axis. However, if an axis is specifically marked as having
 -    // independent ticks, then that is permissible as well.
 -    var opts = this.optionsViewForAxis_('y' + (i ? '2' : ''));
 -    var ticker = opts('ticker');
 -    if (i === 0 || axis.independentTicks) {
 +    
 +    
 +    if(independentTicks) {
 +      axis.independentTicks = independentTicks;
 +      var opts = this.optionsViewForAxis_('y' + (i ? '2' : ''));
 +      var ticker = opts('ticker');
        axis.ticks = ticker(axis.computedValueRange[0],
 -                          axis.computedValueRange[1],
 -                          this.height_,  // TODO(danvk): should be area.height
 -                          opts,
 -                          this);
 -    } else {
 -      var p_axis = this.axes_[0];
 +              axis.computedValueRange[1],
 +              this.height_,  // TODO(danvk): should be area.height
 +              opts,
 +              this);
 +      // Define the first independent axis as primary axis.
 +      if (!p_axis) p_axis = axis;
 +    }
 +  }
 +  if (p_axis === undefined) {
 +    throw ("Configuration Error: At least one axis has to have the \"independentTicks\" option activated.");
 +  }
 +  // Add ticks. By default, all axes inherit the tick positions of the
 +  // primary axis. However, if an axis is specifically marked as having
 +  // independent ticks, then that is permissible as well.
 +  for (var i = 0; i < numAxes; i++) {
 +    var axis = this.axes_[i];
 +    
 +    if (!axis.independentTicks) {
 +      var opts = this.optionsViewForAxis_('y' + (i ? '2' : ''));
 +      var ticker = opts('ticker');
        var p_ticks = p_axis.ticks;
        var p_scale = p_axis.computedValueRange[1] - p_axis.computedValueRange[0];
        var scale = axis.computedValueRange[1] - axis.computedValueRange[0];