Remove Git::LoadCPAN to ensure we use only system perl modules

Git tries very hard to rely on as few non-core modules as possible.  The
few that it does (currently Error and Mail::Address) are bundled.  We've
disabled such bundling since it became an option in 2.17.0.

Go a step further and remove the Git::LoadCPAN wrapper.  This allows
rpm's automatic dependency generator to find and add the needed
requirements.

With this change we can remove the manual 'Requires:' for perl(Error)
and perl(Mail::Address).

'Requires: perl(Error)' in the main git package has been unneeded for
many years.  It was added in edddb83 ("Update to latest upstream
release. Fix some bugs at the same time", 2007-11-27), which was
git-1.5.3.6.  It was needed for 'git svn' and 'git remote'.  'git svn'
requires perl(Git), which in turn requires perl(Error).

In git-1.5.5, 'git remote' was converted to a builtin command in C
rather than perl, removing the perl(Error) dependency.

Lastly, move the 'BuildRequires: perl(Error)' from perl-Git to the main
list of BuildRequires.

git.spec

@@ -139,6 +139,7 @@ BuildRequires:  libsecret-devel
 BuildRequires:  make
 BuildRequires:  openssl-devel
 BuildRequires:  pcre2-devel
+BuildRequires:  perl(Error)
 BuildRequires:  perl(Test)
 %if 0%{?fedora}
 BuildRequires:  perl-generators
@@ -200,7 +201,6 @@ BuildRequires:  time
 
 Requires:       git-core = %{version}-%{release}
 Requires:       git-core-doc = %{version}-%{release}
-Requires:       perl(Error)
 %if ! %{defined perl_bootstrap}
 Requires:       perl(Term::ReadKey)
 %endif
@@ -304,7 +304,6 @@ Summary:        Git tools for sending patches via email
 BuildArch:      noarch
 Requires:       git = %{version}-%{release}, perl-Git = %{version}-%{release}
 Requires:       perl(Authen::SASL)
-Requires:       perl(Mail::Address)
 Requires:       perl(Net::SMTP::SSL)
 Requires:       perl(Git)
 %description email
@@ -362,9 +361,7 @@ Requires:       git = %{version}-%{release}
 %package -n perl-Git
 Summary:        Perl interface to Git
 BuildArch:      noarch
-BuildRequires:  perl(Error)
 Requires:       git = %{version}-%{release}
-Requires:       perl(Error)
 Requires:       perl(:MODULE_COMPAT_%(eval "`%{__perl} -V:version`"; echo $version))
 %description -n perl-Git
 %{summary}.
@@ -480,6 +477,11 @@ EOF
 chmod +x %{__perl_requires}
 %endif
 
+# Remove Git::LoadCPAN to ensure we use only system perl modules.  This also
+# allows the dependencies to be automatically processed by rpm.
+rm -rf perl/Git/LoadCPAN{.pm,/}
+grep -rlZ '^use Git::LoadCPAN::' | xargs -r0 sed -i 's/Git::LoadCPAN:://g'
+
 %build
 make %{?_smp_mflags} all %{?with_docs:doc}
 
@@ -886,6 +888,9 @@ make test || ./print-failed-test-output
 %{?with_docs:%{_pkgdocdir}/git-svn.html}
 
 %changelog
+* Sat Apr 07 2018 Todd Zullinger <tmz@pobox.com>
+- Remove Git::LoadCPAN to ensure we use only system perl modules
+
 * Mon Apr 02 2018 Todd Zullinger <tmz@pobox.com>
 - Allow git-p4 subpackage to be toggled via --with/--without
 - Use %%bcond_(with|without) to enable/disable python3