Bugzilla

I investigated the reason for this issue.
First, even if we get rid of the patch of bug 1185358, we can reproduce a similar issue.

STR: 
1. Copy the following multiline test.
```
java
script:alert(1);
```
2. Paste with middle click

Then a tab will be removed and `alert(1);` is pasted to the URLBar by https://hg.mozilla.org/mozilla-central/rev/e4a60e1d9ef527ebc960f7ebc589b24e9d7681b1#l1.12 .

It seems that a fundamental fix is needed, such as when the tabs are removed by middle-clicking, avoid pasting the value.

I investigated the reason for this issue.
First, even if we get rid of the patch of bug 1185358, we can reproduce a similar issue.

STR: 
1. Copy the following multiline test.
```
java
script:alert(1);
```
2. Paste with middle click

Then a tab will be removed and `alert(1);` is pasted to the URLBar by https://hg.mozilla.org/mozilla-central/rev/e4a60e1d9ef527ebc960f7ebc589b24e9d7681b1#l1.12 .

It seems that a fundamental fix is needed, such as when the tab is removed by middle-clicking, avoid pasting the value.