fix extra newlines when copying from diff in Firefox (#7288)

* fix extra newlines when copying from diff

See https://bugzilla.mozilla.org/show_bug.cgi?id=1273836

Basically, the <pre><code> seems to add a forced newline that is not
possible to get rid of via CSS, so I replaced it with just a <code>.

Secondly, .lines-type-marker also forced a newline in the copied text,
but that was possible to get rid of via user-select.

Safari still has a extraneous newline in the copied text of unknown
origin, but this should not block stop this PR.

* simplify .line-type-marker

* fix selector

* remove erronous ^^^

* Fix empty split diff

* Fix arc-theme-green

* fix add comment

* ensure line-num is copied too

* Update templates/repo/diff/box.tmpl

Co-Authored-By: zeripath <art27@cantab.net>

* attempt to fix safari via removing <code>

* remove useless whitespace at the end of 'class'

* remove inter-tag whitespace for code <td>s

* more inter-tag removal

* final inter-tag removal

* attempt to fix empty line copy

* move and comment getLineContent

* fix golint

* make background grey for missing added code

6 files changed, 24 insertions, 23 deletions

diff --git a/public/css/index.css b/public/css/index.css
index 475a54f75f..5e2c7908e9 100644
--- a/public/css/index.css
+++ b/public/css/index.css
@@ -47,9 +47,9 @@ img{border-radius:3px}
 table{border-collapse:collapse}
 a{cursor:pointer}
 .rounded{border-radius:.28571429rem!important}
-code,pre{font:12px 'SF Mono',Consolas,Menlo,'Liberation Mono',Monaco,'Lucida Console',monospace}
-code.raw,pre.raw{padding:7px 12px;margin:10px 0;background-color:#f8f8f8;border:1px solid #ddd;border-radius:3px;font-size:13px;line-height:1.5;overflow:auto}
-code.wrap,pre.wrap{white-space:pre-wrap;word-break:break-all;overflow-wrap:break-word;word-wrap:break-word}
+.mono,code,pre{font:12px 'SF Mono',Consolas,Menlo,'Liberation Mono',Monaco,'Lucida Console',monospace}
+.mono.raw,code.raw,pre.raw{padding:7px 12px;margin:10px 0;background-color:#f8f8f8;border:1px solid #ddd;border-radius:3px;font-size:13px;line-height:1.5;overflow:auto}
+.mono.wrap,code.wrap,pre.wrap{white-space:pre-wrap;word-break:break-all;overflow-wrap:break-word;word-wrap:break-word}
 .dont-break-out{overflow-wrap:break-word;word-wrap:break-word;word-break:break-all;-webkit-hyphens:auto;-ms-hyphens:auto;hyphens:auto}
 .full.height{flex-grow:1;padding-bottom:80px}
 .following.bar{z-index:900;left:0;margin:0!important}
@@ -638,19 +638,18 @@ footer .ui.left,footer .ui.right{line-height:40px}
 .repository .diff-file-box .file-body.file-code .lines-num-old{border-right:1px solid #ddd}
 .repository .diff-file-box .code-diff{font-size:12px}
 .repository .diff-file-box .code-diff td{padding:0 0 0 10px;border-top:0}
-.repository .diff-file-box .code-diff pre{margin:0}
 .repository .diff-file-box .code-diff .lines-num{border-color:#d4d4d5;border-right-width:1px;border-right-style:solid;padding:0 5px}
 .repository .diff-file-box .code-diff tbody tr td.halfwidth{width:49%}
 .repository .diff-file-box .code-diff tbody tr td.tag-code,.repository .diff-file-box .code-diff tbody tr.tag-code td{background-color:#f0f0f0!important;border-color:#d3cfcf!important;padding-top:8px;padding-bottom:8px}
 .repository .diff-file-box .code-diff tbody tr .removed-code{background-color:#f99}
 .repository .diff-file-box .code-diff tbody tr .added-code{background-color:#9f9}
-.repository .diff-file-box .code-diff tbody tr .lines-num[data-line-num]::before{content:attr(data-line-num);text-align:right}
-.repository .diff-file-box .code-diff tbody tr .lines-type-marker{width:10px;min-width:10px}
-.repository .diff-file-box .code-diff tbody tr .line-type-marker[data-type-marker]::before{content:attr(data-type-marker);text-align:right;display:inline-block}
+.repository .diff-file-box .code-diff tbody tr [data-line-num]::before{content:attr(data-line-num);text-align:right}
+.repository .diff-file-box .code-diff tbody tr .lines-type-marker{width:10px;min-width:10px;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none}
+.repository .diff-file-box .code-diff tbody tr [data-type-marker]::before{content:attr(data-type-marker);text-align:right;display:inline-block}
 .repository .diff-file-box .code-diff-unified tbody tr.del-code td{background-color:#ffe0e0!important;border-color:#f1c0c0!important}
 .repository .diff-file-box .code-diff-unified tbody tr.add-code td{background-color:#d6fcd6!important;border-color:#c1e9c1!important}
 .repository .diff-file-box .code-diff-split table,.repository .diff-file-box .code-diff-split tbody{width:100%}
-.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(5),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(6){background-color:#fafafa}
+.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(3),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(5),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(6){background-color:#fafafa}
 .repository .diff-file-box .code-diff-split tbody tr td.del-code,.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3){background-color:#ffe0e0!important;border-color:#f1c0c0!important}
 .repository .diff-file-box .code-diff-split tbody tr td.add-code,.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(4),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(5),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(6){background-color:#d6fcd6!important;border-color:#c1e9c1!important}
 .repository .diff-file-box .code-diff-split tbody tr td:nth-child(4){border-left-width:1px;border-left-style:solid}
diff --git a/public/css/theme-arc-green.css b/public/css/theme-arc-green.css
index 05cc6e5ebb..f61fd2c96e 100644
--- a/public/css/theme-arc-green.css
+++ b/public/css/theme-arc-green.css
@@ -216,9 +216,9 @@ a.ui.label:hover,a.ui.labels .label:hover{background-color:#505667;color:#dbdbdb
 .ui.basic.blue.button,.ui.basic.blue.buttons .button{box-shadow:0 0 0 1px #a27558 inset!important;color:#a27558!important}
 .repository.file.list #file-content .code-view .hljs,.repository.file.list #file-content .code-view .lines-code ol,.repository.file.list #file-content .code-view .lines-code pre,.repository.file.list #file-content .code-view .lines-num .hljs,.repository.file.list #file-content .code-view .lines-num ol,.repository.file.list #file-content .code-view .lines-num pre{background-color:#2a2e3a}
 a.ui.label:hover,a.ui.labels .label:hover{background-color:#505667;color:#dbdbdb}
-.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4){background-color:#2a2e3a}
-.repository .diff-file-box .code-diff-split tbody tr td.add-code,.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(3),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(4){background-color:#283e2d!important;border-color:#314a37!important}
-.repository .diff-file-box .code-diff-split tbody tr td.del-code,.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(2){background-color:#3c2626!important;border-color:#634343!important}
+.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(5),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(6){background-color:#2a2e3a}
+.repository .diff-file-box .code-diff-split tbody tr td.add-code,.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(4),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(5),.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(6){background-color:#283e2d!important;border-color:#314a37!important}
+.repository .diff-file-box .code-diff-split tbody tr td.del-code,.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(1),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(2),.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3){background-color:#3c2626!important;border-color:#634343!important}
 .ui.blue.button:focus,.ui.blue.buttons .button:focus{background-color:#a27558}
 .ui.blue.button:active,.ui.blue.buttons .button:active{background-color:#a27558}
 #git-graph-container li a{color:#c79575}
diff --git a/public/js/index.js b/public/js/index.js
index 3b2527d986..53fcaa8ba1 100644
--- a/public/js/index.js
+++ b/public/js/index.js
@@ -1069,8 +1069,8 @@ function initPullRequestReview() {
         var ntr = tr.next();
         if (!ntr.hasClass('add-comment')) {
             ntr = $('<tr class="add-comment">'
-                    + (isSplit ? '<td class="lines-num"></td><td class="add-comment-left"></td><td class="lines-num"></td><td class="add-comment-right"></td>'
-                               : '<td class="lines-num"></td><td class="lines-num"></td><td class="add-comment-left add-comment-right"></td>')
+                    + (isSplit ? '<td class="lines-num"></td><td class="lines-type-marker"></td><td class="add-comment-left"></td><td class="lines-num"></td><td class="lines-type-marker"></td><td class="add-comment-right"></td>'
+                               : '<td class="lines-num"></td><td class="lines-num"></td><td class="lines-type-marker"></td><td class="add-comment-left add-comment-right"></td>')
                     + '</tr>');
             tr.after(ntr);
         }
diff --git a/public/less/_base.less b/public/less/_base.less
index 13ae1ad665..213ae2d2e6 100644
--- a/public/less/_base.less
+++ b/public/less/_base.less
@@ -160,7 +160,8 @@ a {
 }
 
 pre,
-code {
+code,
+.mono {
     font: 12px @monospaced-fonts, monospace;
 
     &.raw {
diff --git a/public/less/_repository.less b/public/less/_repository.less
index 8d38faf50c..681296b74d 100644
--- a/public/less/_repository.less
+++ b/public/less/_repository.less
@@ -1362,10 +1362,6 @@
                 border-top: 0;
             }
 
-            pre {
-                margin: 0;
-            }
-
             .lines-num {
                 border-color: #d4d4d5;
                 border-right-width: 1px;
@@ -1405,7 +1401,7 @@
                         background-color: #99ff99;
                     }
 
-                    .lines-num[data-line-num]::before {
+                    [data-line-num]::before {
                         content: attr(data-line-num);
                         text-align: right;
                     }
@@ -1413,9 +1409,10 @@
                     .lines-type-marker {
                         width: 10px;
                         min-width: 10px;
+                        user-select: none;
                     }
 
-                    .line-type-marker[data-type-marker]::before {
+                    [data-type-marker]::before {
                         content: attr(data-type-marker);
                         text-align: right;
                         display: inline-block;
@@ -1448,7 +1445,7 @@
                 // light gray for empty lines before / after commit
                 &.add-code td:nth-child(1),
                 &.add-code td:nth-child(2),
-                &.del-code td:nth-child(3),
+                &.add-code td:nth-child(3),
                 &.del-code td:nth-child(4),
                 &.del-code td:nth-child(5),
                 &.del-code td:nth-child(6) {
diff --git a/public/less/themes/arc-green.less b/public/less/themes/arc-green.less
index d2fe2982d7..463a979434 100644
--- a/public/less/themes/arc-green.less
+++ b/public/less/themes/arc-green.less
@@ -1115,12 +1115,15 @@ a.ui.labels .label:hover {
 .repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(1),
 .repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(2),
 .repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3),
-.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4) {
+.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(4),
+.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(5),
+.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(6) {
     background-color: #2a2e3a;
 }
 
-.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(3),
 .repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(4),
+.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(5),
+.repository .diff-file-box .code-diff-split tbody tr.add-code td:nth-child(6),
 .repository .diff-file-box .code-diff-split tbody tr td.add-code {
     background-color: #283e2d !important;
     border-color: #314a37 !important;
@@ -1128,6 +1131,7 @@ a.ui.labels .label:hover {
 
 .repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(1),
 .repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(2),
+.repository .diff-file-box .code-diff-split tbody tr.del-code td:nth-child(3),
 .repository .diff-file-box .code-diff-split tbody tr td.del-code {
     background-color: #3c2626 !important;
     border-color: #634343 !important;