Bisecting a Regression

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Tim van der Meij edited this page May 8, 2015 · 15 revisions

1) At a minimum you will need:

Git
Node.js

2) Getting PDF.js

Start the git command line
Change to a directory where you want to place PDF.js
Run git clone git://github.com/mozilla/pdf.js.git

3) Open PDF.js

Option 1 - Node.js server

Run cd pdf.js
Run node make server
Open a browser and go to http://localhost:8080/web/viewer.html

Option 2 - Another server

Open a browser and go to http://<yourserver>/pdf.js/web/viewer.html

4) Verify the regression

Download the bad PDF and open it with the above viewer (using, for example, the Open File button in the toolbar) and verify that the PDF is broken

5) Start the bisecting process

Mark the current version as bad using git bisect start and git bisect bad

6) Find bad commit ID

Option 1 - Detecting version / commit of PDF.js installed in Firefox

Open resource://pdf.js/build/pdf.js
Find the commit in the line with 'PDFJS.build = '
Find the version in the line with 'PDFJS.version = '

Option 2 - Using Bugzilla patch

A Bugzilla patch contains the commit information near browser/extensions/pdfjs/content/build/pdf.js [e.g., see https://bug871530.bugzilla.mozilla.org/attachment.cgi?id=750657, was added3d (good), will be 869b878 (bad)]

Option 3 - Using MXR

If you know it was good in the Beta or Aurora branch, get the bad commit ID from MXR. Find the line with 'PDFJS.build = ' and copy the value in the single quotes, e.g., 4e83123.

Aurora: http://mxr.mozilla.org/mozilla-aurora/source/browser/extensions/pdfjs/content/build/pdf.js#24 Beta: http://mxr.mozilla.org/mozilla-beta/source/browser/extensions/pdfjs/content/build/pdf.js#24

7) Verify the working version

git checkout <commit ID that you found above>
Full refresh (CTRL + Shift + R) Firefox and verify that the PDF no longer works
Mark it as good git bisect good

8) Continue bisecting

Full refresh (CTRL + Shift + R) of the viewer in Firefox
If the current version works, mark it using git bisect good
If it fails, mark it using git bisect bad
Repeat the steps above