src/Composer/Repository/Vcs/GitHubDriver.php
public function getBranches()
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getBranches();
        }
        if (null === $this->branches) {
            $this->branches = array();
            $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/git/refs/heads?per_page=100';

            $branchBlacklist = array('gh-pages');

            do {
                $branchData = JsonFile::parseJson($this->getContents($resource), $resource);
                foreach ($branchData as $branch) {
                    $name = substr($branch['ref'], 11);
                    if (!in_array($name, $branchBlacklist)) {
                        $this->branches[$name] = $branch['object']['sha'];
                    }
                }

                $resource = $this->getNextPage();
            } while ($resource);
        }

        return $this->branches;
    }
public function getBranches()
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getBranches();
        }
        if (null === $this->branches) {
            $this->branches = array();
            $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/git/refs/heads?per_page=100';

            $branchBlacklist = array('gh-pages');

            do {
                $branchData = JsonFile::parseJson($this->getContents($resource), $resource);
                foreach ($branchData as $branch) {
                    $name = substr($branch['ref'], 11);
                    if (!in_array($name, $branchBlacklist)) {
                        $this->branches[$name] = $branch['object']['sha'];
                    }
                }

                $resource = $this->getNextPage();
            } while ($resource);
        }

        return $this->branches;
    }
{@inheritDoc}