Backup of code I suggested to Wikipedia.

<includeonly>{{#switch: {{#if: {{{1|}}} |{{{1}}}|int_roman}}
| iint | iiint | iiiint | oint| varointclockwise  | ointctrclockwise | oiint 
| oiiint = <span style{{=}}"display: inline-block; position: relative; line-height: 0.715em; height: 0.715em; <!--
-->margin: {{#ifeq: {{{4|}}} |tiny|-0.4|-1.0}}em 0 {{#ifeq: {{{4|}}} |tiny|0.8|0}}em 0<!-- trbl -->; <!--
-->padding: {{#ifeq: {{{4|}}} |tiny|0.3|0}}em 0 {{#ifeq: {{{4|}}} |tiny|0.7|0}}em 0<!-- trbl -->; font-size: {{#ifeq: {{{4|}}} |tiny|0.6|1.0}}em; {{#ifeq: {{{4|}}} |tiny|vertical-align: 0.3em;}}"><!--
--><span style{{=}}"vertical-align: -0.075em; font-style: italic; font-size: 1.4em; line-height: 0.715em; height: 0.715em; margin-top: -1.0em; padding-top: 0; margin-right: -0.15em;"><!--
-->{{#switch: {{{1|int}}}
   | iint = {{Unicode|∬}}
   | iiint = {{Unicode|∭}} 
   | iiiint = {{Unicode|⨌}} 
   | oint = {{Unicode|∮}}
   | varointclockwise = {{Unicode|∲}} 
   | ointctrclockwise = {{Unicode|∳}}
   | oiint = {{Unicode|∯}}
   | oiiint = {{Unicode|∰}}
   }}<!--
--></span><!--
  -->{{su
     | b = <span style{{=}}"vertical-align: -0.25em; font-size: 0.9em; margin-left: -0.1em;">{{{2|}}}</span>
     | p = <span style{{=}}"vertical-align: 0em; font-size: 0.9em; margin-left: 0.4em;">{{{3|}}}</span>
     }}<!--
--></span>
| int_italic | int_oblique 
| int = {{intmath/int/sandbox|{{{2|}}}|{{{3|}}}|{{{4|}}}}}<noinclude><!--

  *****
 
  This code, which shall be in Template:Intmath/int subtemplate (so we can call it to implement the idotsint option), is now in
  Template:Intmath/int/sandbox (obviously, with {{{2|}}}, {{{3|}}}, {{{4|}}} replaced by {{{1|}}}, {{{2|}}}, {{{3|}}})   

  *****

--><span style{{=}}"display: inline-block; position: relative; line-height: 0.715em; height: 0.715em; margin-top: -1.0em; padding: 0; font-size: {{#ifeq: {{{4|}}} |tiny|0.75|1.0}}em; {{#ifeq: {{{4|}}} |tiny|vertical-align: 0.3em;}}"><!--
--><span style{{=}}"display: inline-block; vertical-align: -0.11em; line-height: 0.715em; height: 0.715em; padding-top: 0; margin-right: -0.15em;"><!--
--><span style{{=}}"font-size: 1.4em; line-height: 0.715em; height: 0.715em; {{transform-rotate|18.5}} vertical-align: -0.13em; margin-top: -1.0em; padding-top: 0; margin-right: -0.25em;">{{Unicode|∫}}</span><!--
  -->{{su
     | b = <span style{{=}}"vertical-align: 0.0em; font-size: 0.9em; margin-left: 0.3em;">{{{2|}}}</span>
     | p = <span style{{=}}"vertical-align: 0.0em; font-size: 0.9em; margin-left: 0.9em;">{{{3|}}}</span>
     }}<!--
--></span></span>

</noinclude>
| idotsint = {{intmath/int/sandbox|||{{{4|}}}}}{{nbsp|2}}⋯<!-- ⋯ --> <!-- hair space --><!--
-->{{intmath/int/sandbox|{{{2|}}}|{{{3|}}}|{{{4|}}}}}  <!-- 2 hair spaces -->
| int_roman | int_normal 
| #default = <!--
--><span style{{=}}"display: inline-block; position: relative; font-size: {{#ifeq: {{{4|}}} |tiny|0.75|1.0}}em; {{#ifeq: {{{4|}}} |tiny|vertical-align: 0.3em;}} line-height: 0.715em; height: 0.715em; margin-top: -1.0em; padding: 0;"><!--
  --><span style{{=}}"vertical-align: -0.15em; font-style: italic; font-size: 1.35em; margin-right: -0.06em;">{{Unicode|∫}}</span><!--
  -->{{su
     | b = <span style{{=}}"vertical-align: -0.1em; font-size: 0.9em; margin-left: 0.1em;">{{{2|}}}</span>
     | p = <span style{{=}}"vertical-align: -0.5em; font-size: 0.9em; margin-left: 0.2em;">{{{3|}}}</span>
     }}<!--
--></span><!--
-->}}</includeonly><noinclude>
{{documentation}}
</noinclude>

<noinclude>Sandbox for italic int which shall be implemented in <code>{{tl|intmath/int}}</code> subtemplate so that it can be called from <code>{{tl|intmath}}</code> to implement the <code>idotsint</code> option, e.g.

<code>{{math| H {{=}} {{intmath/sandbox|idotsint|''n''-ball}} ''dH'' }}</code> yields the HTML text style {{math| H {{=}} {{intmath/sandbox|idotsint|''n''-ball}} ''dH'' }}

<code>{{bigmath| H {{=}} {{intmath/sandbox|idotsint|''n''-ball}} ''dH'' }}</code> yields the HTML display style  

:{{bigmath| H {{=}} {{intmath/sandbox|idotsint|''n''-ball}} ''dH'' }}
</noinclude><includeonly><!--

Italic int implemented as Template:Intmath/int subtemplate so that it can be called from Template:Intmath to implement idotsint.  

--><span style{{=}}"display: inline-block; position: relative; line-height: 0.715em; height: 0.715em; margin-top: -1.0em; padding: 0; font-size: {{#ifeq: {{{3|}}} |tiny|0.75|1.0}}em; {{#ifeq: {{{3|}}} |tiny|vertical-align: 0.35em;}}"><!--
--><span style{{=}}"display: inline-block; vertical-align: -0.11em; line-height: 0.715em; height: 0.715em; padding-top: 0; margin-right: -0.15em;"><!--
--><span style{{=}}"font-size: 1.4em; line-height: 0.715em; height: 0.715em; {{transform-rotate|18.5}} vertical-align: -0.13em; margin-top: -1.0em; padding-top: 0; margin-right: -0.25em;">{{Unicode|∫}}</span><!--
  -->{{su
     | b = <span style{{=}}"vertical-align: 0.0em; font-size: 0.9em; margin-left: 0.3em;">{{{1|}}}</span>
     | p = <span style{{=}}"vertical-align: 0.0em; font-size: 0.9em; margin-left: 0.9em;">{{{2|}}}</span>
     }}<!--
--></span></span></includeonly>