Don't allow output to overflow page width.

IPython/html/static/notebook/less/outputarea.less

@@ -1,190 +1,192 b''
 div.output_wrapper {
     /* this position must be relative to enable descendents to be absolute within it */
     position: relative;
     .vbox()
 }
 
 /* class for the output area when it should be height-limited */
 div.output_scroll {
     /* ideally, this would be max-height, but FF barfs all over that */
     height: 24em;
     /* FF needs this *and the wrapper* to specify full width, or it will shrinkwrap */
     width: 100%;
 
     overflow: auto;
     .corner-all;
     .box-shadow(inset 0 2px 8px rgba(0, 0, 0, .8));
     display: block;
 }
 
 /* output div while it is collapsed */
 div.output_collapsed {
     margin: 0px;
     padding: 0px;
     .vbox();
 }
 
 div.out_prompt_overlay {
     height: 100%;
     padding: 0px @code_padding;
     position: absolute;
     .corner-all;
 }
 
 div.out_prompt_overlay:hover {
     /* use inner shadow to get border that is computed the same on WebKit/FF */
     .box-shadow(inset 0 0 1px #000);
     background: rgba(240, 240, 240, 0.5);
 }
 
 div.output_prompt {
     color: @output_prompt_color;
 }
 
 /* This class is the outer container of all output sections. */
 div.output_area {
     padding: 0px;
     page-break-inside: avoid;
     .hbox();
 
     .MathJax_Display {
         // Inside a CodeCell, elements are left justified
         text-align: left !important;
     }
 
     .rendered_html {
         // Inside a CodeCell, elements are left justified
         table {
             margin-left: 0;
             margin-right: 0;
         }
     
         img {
             margin-left: 0;
             margin-right: 0;
         }
     }
 }
 
 /* This is needed to protect the pre formating from global settings such
    as that of bootstrap */
 .output {
     .vbox();
 }
 
 @media (max-width: @screen-xs-min) {
     // move prompts above output on small screens
     div.output_area {
         .vbox();
     }
 }
 
 div.output_area pre {
     margin: 0;
     padding: 0;
     border: 0;
     vertical-align: baseline;
     color: @output_pre_color;
     background-color: transparent;
     .border-radius(0);
 }
 
 /* This class is for the output subarea inside the output_area and after
    the prompt div. */
 div.output_subarea {
+    // Don't let contents overflow page area.
+    overflow-x: auto;
     padding: @code_padding;
     .box-flex1();
 }
 
 /* The rest of the output_* classes are for special styling of the different
    output types */
 
 /* all text output has this class: */
 div.output_text {
     text-align: left;
     color: @text-color;
     /* This has to match that of the the CodeMirror class line-height below */  
     line-height: @code_line_height;
 }
 
 /* stdout/stderr are 'text' as well as 'stream', but execute_result/error are *not* streams */
 div.output_stream {
 }
 
 div.output_stdout {
 }
 
 div.output_stderr {
     background: #fdd; /* very light red background for stderr */
 }
 
 div.output_latex {
     text-align: left;
 }
 
 div.output_html {
 }
 
 div.output_png {
 }
 
 div.output_jpeg {
 }
 
 /* Empty output_javascript divs should have no height */
 div.output_javascript:empty {
     padding: 0;
 }
 
 .js-error {
     color: darkred;
 }
 
 /* raw_input styles */
 
 div.raw_input_container {
     font-family: @font-family-monospace;
     // for some reason, em padding doesn't compute the same for raw_input
     // that is not the first input, but px does
     padding-top: 5px;
 }
 
 span.raw_input_prompt {
     /* nothing needed here */
 }
 
 input.raw_input {
     font-family: inherit;
     font-size: inherit;
     color: inherit;
     width: auto;
     /* make sure input baseline aligns with prompt */
     vertical-align: baseline;
     /* padding + margin = 0.5em between prompt and cursor */
     padding: 0em 0.25em;
     margin: 0em 0.25em;
 }
 
 input.raw_input:focus {
     box-shadow: none;
 }
 
 p.p-space {
     margin-bottom: 10px;
 }
 
 div.output_unrecognized {
   padding: 5px;
   font-weight: bold;
   color: red;
   // remove decoration from link
   a {
       color: inherit;
       text-decoration: none;
 
       &:hover {
           color: inherit;
           text-decoration: none;
       }
   }
 }