[PATCH] gitweb: Use GITWEB_CONFIG_SYSTEM even if GITWEB_CONFIG does exist

[Jakub Narebski <jnareb@gmail.com>]

gitweb obtains configuration from the following sources:

  1. per-instance configuration file (default: gitweb_conf.perl)
  2. system-wide configuration file (default: /etc/gitweb.conf)

If per-instance configuration file exists, then system-wide
configuration was _not used at all_.  This is quite untypical and
suprising behavior.

This commit changes gitweb behavior so that configuration in
per-instance configuration file can _override_ settings from
system-wide configuration file.

Suggested-by: Drew Northup <drew.northup@maine.edu>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
This is the response to discussion in the

  [PATCH/WIP] Starting work on a man page for /etc/gitweb.conf
  http://thread.gmane.org/gmane.comp.version-control.git/173422

The patch to gitweb.perl itself (without the commit message) was send
as part of 

  http://thread.gmane.org/gmane.comp.version-control.git/173422/focus=173489

(embedded in body of email).

Note that changes to gitweb/README and gitweb/INSTALL were
minimalized, so the final result might not be the best... but I think
it is good enough.

 gitweb/INSTALL     |    8 +++++---
 gitweb/README      |    2 +-
 gitweb/gitweb.perl |    7 ++++---
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/gitweb/INSTALL b/gitweb/INSTALL
index 4964a67..0584919 100644
--- a/gitweb/INSTALL
+++ b/gitweb/INSTALL
@@ -98,15 +98,17 @@ Gitweb config file
 See also "Runtime gitweb configuration" section in README file
 for gitweb (in gitweb/README).
 
-- You can configure gitweb further using the gitweb configuration file;
+- You can configure gitweb further using the per-instance gitweb configuration file;
   by default this is a file named gitweb_config.perl in the same place as
   gitweb.cgi script. You can control the default place for the config file
   using the GITWEB_CONFIG build configuration variable, and you can set it
-  using the GITWEB_CONFIG environment variable. If this file does not
-  exist, gitweb looks for a system-wide configuration file, normally
+  using the GITWEB_CONFIG environment variable.
+  gitweb also looks for a system-wide configuration file, normally
   /etc/gitweb.conf. You can change the default using the
   GITWEB_CONFIG_SYSTEM build configuration variable, and override it
   through the GITWEB_CONFIG_SYSTEM environment variable.
+  Settings from per-instance configuration file override those from
+  system-wide configuration file.
 
 - The gitweb config file is a fragment of perl code. You can set variables
   using "our $variable = value"; text from "#" character until the end
diff --git a/gitweb/README b/gitweb/README
index a92bde7..334f13e 100644
--- a/gitweb/README
+++ b/gitweb/README
@@ -126,7 +126,7 @@ Runtime gitweb configuration
 
 You can adjust gitweb behaviour using the file specified in `GITWEB_CONFIG`
 (defaults to 'gitweb_config.perl' in the same directory as the CGI), and
-as a fallback `GITWEB_CONFIG_SYSTEM` (defaults to /etc/gitweb.conf).
+`GITWEB_CONFIG_SYSTEM` (defaults to /etc/gitweb.conf), in that order.
 The most notable thing that is not configurable at compile time are the
 optional features, stored in the '%features' variable.
 
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index acdc5b8..9527cd2 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -637,12 +637,13 @@ sub evaluate_gitweb_config {
 	our $GITWEB_CONFIG = $ENV{'GITWEB_CONFIG'} || "++GITWEB_CONFIG++";
 	our $GITWEB_CONFIG_SYSTEM = $ENV{'GITWEB_CONFIG_SYSTEM'} || "++GITWEB_CONFIG_SYSTEM++";
 	# die if there are errors parsing config file
+	if (-e $GITWEB_CONFIG_SYSTEM) {
+		do $GITWEB_CONFIG_SYSTEM;
+		die $@ if $@;
+	}
 	if (-e $GITWEB_CONFIG) {
 		do $GITWEB_CONFIG;
 		die $@ if $@;
-	} elsif (-e $GITWEB_CONFIG_SYSTEM) {
-		do $GITWEB_CONFIG_SYSTEM;
-		die $@ if $@;
 	}
 }
 
-- 
1.7.5