avoid missing gridlines on rangebreaks with pattern day of week

- round 2 days to 1 day
- round 3 days to 7 days

Author: archmoj

src/plots/cartesian/axes.js

@@ -807,6 +807,12 @@ axes.autoTicks = function(ax, roughDTick) {
             ax.dtick = 'M' + roundDTick(roughDTick, 1, roundBase24);
         } else if(roughX2 > ONEDAY) {
             ax.dtick = roundDTick(roughDTick, ONEDAY, roundDays);
+
+            if(ax._hasDayOfWeekBreaks) {
+                if(ax.dtick === 2 * ONEDAY) ax.dtick = ONEDAY;
+                else if(ax.dtick === 3 * ONEDAY) ax.dtick = 7 * ONEDAY;
+            }
+
             // get week ticks on sunday
             // this will also move the base tick off 2000-01-01 if dtick is
             // 2 or 3 days... but that's a weird enough case that we'll ignore it.

src/plots/cartesian/axis_defaults.js

@@ -135,6 +135,13 @@ module.exports = function handleAxisDefaults(containerIn, containerOut, coerce,
         if(!containerOut.rangebreaks.length) {
             delete containerOut.rangebreaks;
         } else {
+            for(var k = 0; k < containerOut.rangebreaks.length; k++) {
+                if(containerOut.rangebreaks[k].pattern === DAY_OF_WEEK) {
+                    containerOut._hasDayOfWeekBreaks = true;
+                    break;
+                }
+            }
+
             setConvert(containerOut, layoutOut);
 
             if(layoutOut._has('scattergl') || layoutOut._has('splom')) {