Allow image hover previews to use full width of screen.

src/General/UI.coffee

@@ -308,7 +308,7 @@ dragend = ->
     $.off d, 'mouseup',   @up
   $.set "#{@id}.position", @style.cssText
 
-hoverstart = ({root, el, latestEvent, endEvents, height, cb, noRemove}) ->
+hoverstart = ({root, el, latestEvent, endEvents, height, width, cb, noRemove}) ->
   o = {
     root
     el
@@ -320,6 +320,7 @@ hoverstart = ({root, el, latestEvent, endEvents, height, cb, noRemove}) ->
     clientHeight: doc.clientHeight
     clientWidth:  doc.clientWidth
     height
+    width
     noRemove
   }
   o.hover    = hover.bind    o
@@ -344,6 +345,7 @@ hoverstart.padding = 25
 hover = (e) ->
   @latestEvent = e
   height = (@height or @el.offsetHeight) + hoverstart.padding
+  width  = (@width  or @el.offsetWidth)
   {clientX, clientY} = e
 
   top = if @isImage
@@ -353,10 +355,10 @@ hover = (e) ->
 
   threshold = @clientWidth / 2
   threshold = Math.max threshold, @clientWidth - 400 unless @isImage
-  [left, right] = if clientX <= threshold
-    [clientX + 45 + 'px', '']
-  else
-    ['', @clientWidth - clientX + 45 + 'px']
+  marginX = (if clientX <= threshold then clientX else @clientWidth - clientX) + 45
+  marginX = Math.min(marginX, @clientWidth - width) if @isImage
+  marginX += 'px'
+  [left, right] = if clientX <= threshold then [marginX, ''] else ['', marginX]
 
   {style} = @
   style.top   = top + 'px'

src/Images/ImageHover.coffee

@@ -48,7 +48,7 @@ ImageHover =
         @currentTime = el.currentTime if @nodeName is 'VIDEO'
     [width, height] = (+x for x in file.dimensions.split 'x')
     {left, right} = @getBoundingClientRect()
-    maxWidth = Math.max left, doc.clientWidth - right
+    maxWidth = doc.clientWidth
     maxHeight = doc.clientHeight - UI.hover.padding
     scale = Math.min 1, maxWidth / width, maxHeight / height
     el.style.maxWidth  = "#{scale * width}px"
@@ -59,6 +59,7 @@ ImageHover =
       latestEvent: e
       endEvents: 'mouseout click'
       height: scale * height
+      width: scale * width
       noRemove: true
       cb: ->
         $.off el, 'error', error

src/css/style.css

@@ -1344,6 +1344,9 @@ span.hide-announcement {
 .fileThumb > .warning {
   clear: both;
 }
+#ihover {
+  pointer-events: none;
+}
 /* WEBM Metadata */
 .webm-title > a::before {
   content: "title";