[PATCHv3 0/4 (resent)] Miscelanous gitweb improvements from J.H.

@@ -233,6 +233,9 @@ not include variables usually directly set during build):
    If server load exceed this value then return "503 Service Unavailable" error.
    Server load is taken to be 0 if gitweb cannot determine its value.  Set it to
    undefined value to turn it off.  The default is 300.
+ * $git_versions_must_match
+   If set, gitweb fails with 500 Internal Server Error if the version of gitweb
+   doesn't match version of git binary.  The default is false.
 
 
 Projects list file format

@@ -221,6 +221,9 @@ our %avatar_size = (
 	'double'  => 32
 );
 
+# If it is true, exit if gitweb version and git binary version don't match
+our $git_versions_must_match = 0;
+
 # Used to set the maximum load that we will still respond to gitweb queries.
 # If server load exceed this value then return "503 server busy" error.
 # If gitweb cannot determined server load, it is taken to be 0.

@@ -581,6 +584,36 @@ if (defined $maxload && get_loadavg() > $maxload) {
 our $git_version = qx("$GIT" --version) =~ m/git version (.*)$/ ? $1 : "unknown";
 $number_of_git_cmds++;
 
+# Throw an error if git versions does not match, if $git_versions_must_match is true.
+if ($git_versions_must_match &&
+    $git_version ne $version) {
+	git_header_html('500 - Internal Server Error');
+	my $admin_contact =
+		defined $ENV{'SERVER_ADMIN'} ? ", $ENV{'SERVER_ADMIN'}," : '';
+	print <<"EOT";
+<div class="page_body">
+<br /><br />
+500 - Internal Server Error
+<br />
+</div>
+<hr />
+<div class="readme">
+<h1 align="center">*** Warning ***</h1>
+<p>
+This version of gitweb was compiled for <b>@{[esc_html($version)]}</b>,
+however git version <b>@{[esc_html($git_version)]}</b> was found on server,
+and administrator requested strict version checking.
+</p>
+<p>
+Please contact the server administrator${admin_contact} to either configure
+gitweb to allow mismatched versions, or update git or gitweb installation.
+</p>
+</div>
+EOT
+	git_footer_html();
+	exit;
+}
+
 $projects_list ||= $projectroot;
 
 # ======================================================================

@@ -282,29 +282,6 @@ pathsep = :
 # JavaScript minifier invocation that can function as filter
 JSMIN =
 
-# default configuration for gitweb
-GITWEB_CONFIG = gitweb_config.perl
-GITWEB_CONFIG_SYSTEM = /etc/gitweb.conf
-GITWEB_HOME_LINK_STR = projects
-GITWEB_SITENAME =
-GITWEB_PROJECTROOT = /pub/git
-GITWEB_PROJECT_MAXDEPTH = 2007
-GITWEB_EXPORT_OK =
-GITWEB_STRICT_EXPORT =
-GITWEB_BASE_URL =
-GITWEB_LIST =
-GITWEB_HOMETEXT = indextext.html
-GITWEB_CSS = gitweb.css
-GITWEB_LOGO = git-logo.png
-GITWEB_FAVICON = git-favicon.png
-ifdef JSMIN
-GITWEB_JS = gitweb.min.js
-else
-GITWEB_JS = gitweb.js
-endif
-GITWEB_SITE_HEADER =
-GITWEB_SITE_FOOTER =
-
 export prefix bindir sharedir sysconfdir
 
 CC = gcc

@@ -1526,6 +1503,11 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)): % : %.perl
 	chmod +x $@+ && \
 	mv $@+ $@
 
+
+.PHONY: gitweb
+gitweb:
+	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) all
+
 ifdef JSMIN
 OTHER_PROGRAMS += gitweb/gitweb.cgi   gitweb/gitweb.min.js
 gitweb/gitweb.cgi: gitweb/gitweb.perl gitweb/gitweb.min.js

@@ -1533,30 +1515,13 @@ else
 OTHER_PROGRAMS += gitweb/gitweb.cgi
 gitweb/gitweb.cgi: gitweb/gitweb.perl
 endif
-	$(QUIET_GEN)$(RM) $@ $@+ && \
-	sed -e '1s|#!.*perl|#!$(PERL_PATH_SQ)|' \
-	    -e 's|++GIT_VERSION++|$(GIT_VERSION)|g' \
-	    -e 's|++GIT_BINDIR++|$(bindir)|g' \
-	    -e 's|++GITWEB_CONFIG++|$(GITWEB_CONFIG)|g' \
-	    -e 's|++GITWEB_CONFIG_SYSTEM++|$(GITWEB_CONFIG_SYSTEM)|g' \
-	    -e 's|++GITWEB_HOME_LINK_STR++|$(GITWEB_HOME_LINK_STR)|g' \
-	    -e 's|++GITWEB_SITENAME++|$(GITWEB_SITENAME)|g' \
-	    -e 's|++GITWEB_PROJECTROOT++|$(GITWEB_PROJECTROOT)|g' \
-	    -e 's|"++GITWEB_PROJECT_MAXDEPTH++"|$(GITWEB_PROJECT_MAXDEPTH)|g' \
-	    -e 's|++GITWEB_EXPORT_OK++|$(GITWEB_EXPORT_OK)|g' \
-	    -e 's|++GITWEB_STRICT_EXPORT++|$(GITWEB_STRICT_EXPORT)|g' \
-	    -e 's|++GITWEB_BASE_URL++|$(GITWEB_BASE_URL)|g' \
-	    -e 's|++GITWEB_LIST++|$(GITWEB_LIST)|g' \
-	    -e 's|++GITWEB_HOMETEXT++|$(GITWEB_HOMETEXT)|g' \
-	    -e 's|++GITWEB_CSS++|$(GITWEB_CSS)|g' \
-	    -e 's|++GITWEB_LOGO++|$(GITWEB_LOGO)|g' \
-	    -e 's|++GITWEB_FAVICON++|$(GITWEB_FAVICON)|g' \
-	    -e 's|++GITWEB_JS++|$(GITWEB_JS)|g' \
-	    -e 's|++GITWEB_SITE_HEADER++|$(GITWEB_SITE_HEADER)|g' \
-	    -e 's|++GITWEB_SITE_FOOTER++|$(GITWEB_SITE_FOOTER)|g' \
-	    $< >$@+ && \
-	chmod +x $@+ && \
-	mv $@+ $@
+	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) $(patsubst gitweb/%,%,$@)
+
+ifdef JSMIN
+gitweb/gitweb.min.js: gitweb/gitweb.js
+	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) $(patsubst gitweb/%,%,$@)
+endif # JSMIN
+
 
 git-instaweb: git-instaweb.sh gitweb/gitweb.cgi gitweb/gitweb.css gitweb/gitweb.js
 	$(QUIET_GEN)$(RM) $@ $@+ && \

@@ -1583,12 +1548,6 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
 	mv $@+ $@
 endif # NO_PERL
 
-
-ifdef JSMIN
-gitweb/gitweb.min.js: gitweb/gitweb.js
-	$(QUIET_GEN)$(JSMIN) <$< >$@
-endif # JSMIN
-
 ifndef NO_PYTHON
 $(patsubst %.py,%,$(SCRIPT_PYTHON)): GIT-CFLAGS
 $(patsubst %.py,%,$(SCRIPT_PYTHON)): % : %.py

@@ -0,0 +1,129 @@
+# The default target of this Makefile is...
+all::
+
+# Define V=1 to have a more verbose compile.
+#
+# Define JSMIN to point to JavaScript minifier that functions as
+# a filter to have gitweb.js minified.
+#
+
+prefix ?= $(HOME)
+bindir ?= $(prefix)/bin
+RM ?= rm -f
+
+# JavaScript minifier invocation that can function as filter
+JSMIN ?=
+
+# default configuration for gitweb
+GITWEB_CONFIG = gitweb_config.perl
+GITWEB_CONFIG_SYSTEM = /etc/gitweb.conf
+GITWEB_HOME_LINK_STR = projects
+GITWEB_SITENAME =
+GITWEB_PROJECTROOT = /pub/git
+GITWEB_PROJECT_MAXDEPTH = 2007
+GITWEB_EXPORT_OK =
+GITWEB_STRICT_EXPORT =
+GITWEB_BASE_URL =
+GITWEB_LIST =
+GITWEB_HOMETEXT = indextext.html
+GITWEB_CSS = gitweb.css
+GITWEB_LOGO = git-logo.png
+GITWEB_FAVICON = git-favicon.png
+ifdef JSMIN
+GITWEB_JS = gitweb.min.js
+else
+GITWEB_JS = gitweb.js
+endif
+GITWEB_SITE_HEADER =
+GITWEB_SITE_FOOTER =
+
+# include user config
+-include ../config.mak.autogen
+-include ../config.mak
+
+# determine version
+../GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
+	$(QUIET_SUBDIR0)../ $(QUIET_SUBDIR1) GIT-VERSION-FILE
+
+-include ../GIT-VERSION-FILE
+
+### Build rules
+
+SHELL_PATH ?= $(SHELL)
+PERL_PATH  ?= /usr/bin/perl
+
+# Shell quote;
+bindir_SQ = $(subst ','\'',$(bindir))         #'
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH)) #'
+PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))  #'
+
+# Quiet generation (unless V=1)
+QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
+QUIET_SUBDIR1  =
+
+ifneq ($(findstring $(MAKEFLAGS),w),w)
+PRINT_DIR = --no-print-directory
+else # "make -w"
+NO_SUBDIR = :
+endif
+
+ifneq ($(findstring $(MAKEFLAGS),s),s)
+ifndef V
+	QUIET          = @
+	QUIET_GEN      = $(QUIET)echo '   ' GEN $@;
+	QUIET_SUBDIR0  = +@subdir=
+	QUIET_SUBDIR1  = ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
+	                 $(MAKE) $(PRINT_DIR) -C $$subdir
+	export V
+	export QUIET
+	export QUIET_GEN
+	export QUIET_SUBDIR0
+	export QUIET_SUBDIR1
+endif
+endif
+
+all:: gitweb.cgi
+
+ifdef JSMIN
+FILES=gitweb.cgi gitweb.min.js
+gitweb.cgi: gitweb.perl gitweb.min.js
+else # !JSMIN
+FILES=gitweb.cgi
+gitweb.cgi: gitweb.perl
+endif # JSMIN
+
+gitweb.cgi:
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	sed -e '1s|#!.*perl|#!$(PERL_PATH_SQ)|' \
+	    -e 's|++GIT_VERSION++|$(GIT_VERSION)|g' \
+	    -e 's|++GIT_BINDIR++|$(bindir)|g' \
+	    -e 's|++GITWEB_CONFIG++|$(GITWEB_CONFIG)|g' \
+	    -e 's|++GITWEB_CONFIG_SYSTEM++|$(GITWEB_CONFIG_SYSTEM)|g' \
+	    -e 's|++GITWEB_HOME_LINK_STR++|$(GITWEB_HOME_LINK_STR)|g' \
+	    -e 's|++GITWEB_SITENAME++|$(GITWEB_SITENAME)|g' \
+	    -e 's|++GITWEB_PROJECTROOT++|$(GITWEB_PROJECTROOT)|g' \
+	    -e 's|"++GITWEB_PROJECT_MAXDEPTH++"|$(GITWEB_PROJECT_MAXDEPTH)|g' \
+	    -e 's|++GITWEB_EXPORT_OK++|$(GITWEB_EXPORT_OK)|g' \
+	    -e 's|++GITWEB_STRICT_EXPORT++|$(GITWEB_STRICT_EXPORT)|g' \
+	    -e 's|++GITWEB_BASE_URL++|$(GITWEB_BASE_URL)|g' \
+	    -e 's|++GITWEB_LIST++|$(GITWEB_LIST)|g' \
+	    -e 's|++GITWEB_HOMETEXT++|$(GITWEB_HOMETEXT)|g' \
+	    -e 's|++GITWEB_CSS++|$(GITWEB_CSS)|g' \
+	    -e 's|++GITWEB_LOGO++|$(GITWEB_LOGO)|g' \
+	    -e 's|++GITWEB_FAVICON++|$(GITWEB_FAVICON)|g' \
+	    -e 's|++GITWEB_JS++|$(GITWEB_JS)|g' \
+	    -e 's|++GITWEB_SITE_HEADER++|$(GITWEB_SITE_HEADER)|g' \
+	    -e 's|++GITWEB_SITE_FOOTER++|$(GITWEB_SITE_FOOTER)|g' \
+	    $< >$@+ && \
+	chmod +x $@+ && \
+	mv $@+ $@
+
+ifdef JSMIN
+gitweb.min.js: gitweb.js
+	$(QUIET_GEN)$(JSMIN) <$< >$@
+endif # JSMIN
+
+clean:
+	$(RM) $(FILES)
+
+.PHONY: all clean .FORCE-GIT-VERSION-FILE

@@ -71,6 +71,7 @@ You can specify the following configuration variables when building GIT:
  * GITWEB_BASE_URL
    Git base URLs used for URL to where fetch project from, i.e. full
    URL is "$git_base_url/$project".  Shown on projects summary page.
+   If it begins with "git://" it is also used for $gitlinkurl_base, see below.
    Repository URL for project can be also configured per repository; this
    takes precedence over URLs composed from base URL and a project name.
    Note that you can setup multiple base URLs (for example one for

@@ -204,6 +205,9 @@ not include variables usually directly set during build):
    access, and one for http:// "dumb" protocol access).  Note that per
    repository configuration in 'cloneurl' file, or as values of gitweb.url
    project config.
+ * $gitlinkurl_base
+   Git base URL used (if it is defined and not empty) for "git" link in
+   projects list, for each project.  Full URL is "$gitlinkurl_base/$project".
  * $default_blob_plain_mimetype
    Default mimetype for blob_plain (raw) view, if mimetype checking
    doesn't result in some other type; by default 'text/plain'.

@@ -224,6 +224,10 @@ our %avatar_size = (
 # If it is true, exit if gitweb version and git binary version don't match
 our $git_versions_must_match = 0;
 
+# If this variable is set and not empty, add an extra link called "git"
+# for each project in project list.  Full URL is "$gitlinkurl_base/$project".
+our $gitlinkurl_base = ("++GITWEB_BASE_URL++" =~ m!^(git://.*)$!) ? $1 : '';
+
 # Used to set the maximum load that we will still respond to gitweb queries.
 # If server load exceed this value then return "503 server busy" error.
 # If gitweb cannot determined server load, it is taken to be 0.

@@ -4472,6 +4476,10 @@ sub git_project_list_body {
 		      $cgi->a({-href => href(project=>$pr->{'path'}, action=>"log")}, "log") . " | " .
 		      $cgi->a({-href => href(project=>$pr->{'path'}, action=>"tree")}, "tree") .
 		      ($pr->{'forks'} ? " | " . $cgi->a({-href => href(project=>$pr->{'path'}, action=>"forks")}, "forks") : '') .
+		      ($gitlinkurl_base ?
+		       " | " . $cgi->a({-href=>"$gitlinkurl_base/$pr->{'path'}",
+		                        -rel=>"vcs-git"}, "git")
+		      : '') .
 		      "</td>\n" .
 		      "</tr>\n";
 	}

@@ -174,7 +174,7 @@ not include variables usually directly set during build):
    Base URL for relative URLs in pages generated by gitweb,
    (e.g. $logo, $favicon, @stylesheets if they are relative URLs),
    needed and used only for URLs with nonempty PATH_INFO via
-   <base href="$base_url>.  Usually gitweb sets its value correctly,
+   <base href="$base_url">.  Usually gitweb sets its value correctly,
    and there is no need to set this variable, e.g. to $my_uri or "/".
  * $home_link
    Target of the home link on top of all pages (the first part of view

@@ -228,6 +228,11 @@ not include variables usually directly set during build):
    repositories from launching cross-site scripting (XSS) attacks.  Set this
    to true if you don't trust the content of your repositories. The default
    is false.
+ * $maxload
+   Used to set the maximum load that we will still respond to gitweb queries.
+   If server load exceed this value then return "503 Service Unavailable" error.
+   Server load is taken to be 0 if gitweb cannot determine its value.  Set it to
+   undefined value to turn it off.  The default is 300.
 
 
 Projects list file format

@@ -221,6 +221,12 @@ our %avatar_size = (
 	'double'  => 32
 );
 
+# Used to set the maximum load that we will still respond to gitweb queries.
+# If server load exceed this value then return "503 server busy" error.
+# If gitweb cannot determined server load, it is taken to be 0.
+# Leave it undefined (or set to 'undef') to turn off load checking.
+our $maxload = 300;
+
 # You define site-wide feature defaults here; override them with
 # $GITWEB_CONFIG as necessary.
 our %feature = (

@@ -551,6 +557,26 @@ if (-e $GITWEB_CONFIG) {
 	do $GITWEB_CONFIG_SYSTEM if -e $GITWEB_CONFIG_SYSTEM;
 }
 
+# Get loadavg of system, to compare against $maxload.
+# Currently it requires '/proc/loadavg' present to get loadavg;
+# if it is not present it returns 0, which means no load checking.
+sub get_loadavg {
+	open my $fd, '<', '/proc/loadavg'
+		or return 0;
+	my @load = split(/\s+/, scalar <$fd>);
+	close $fd;
+
+	# The first three columns measure CPU and IO utilization of the last one,
+	# five, and 10 minute periods.  The fourth column shows the number of
+	# currently running processes and the total number of processes in the m/n
+	# format.  The last column displays the last process ID used.
+	return $load[0] || 0;
+}
+
+if (defined $maxload && get_loadavg() > $maxload) {
+	die_error(503, "The load average on the server is too high");
+}
+
 # version of the core git binary
 our $git_version = qx("$GIT" --version) =~ m/git version (.*)$/ ? $1 : "unknown";
 $number_of_git_cmds++;

@@ -3354,14 +3380,19 @@ sub git_footer_html {
 # 500: The server isn't configured properly, or
 #      an internal error occurred (e.g. failed assertions caused by bugs), or
 #      an unknown error occurred (e.g. the git binary died unexpectedly).
+# 503: The server is currently unavailable (because it is overloaded,
+#      or down for maintenance).  Generally, this is a temporary state.
 sub die_error {
 	my $status = shift || 500;
 	my $error = shift || "Internal server error";
 
-	my %http_responses = (400 => '400 Bad Request',
-			      403 => '403 Forbidden',
-			      404 => '404 Not Found',
-			      500 => '500 Internal Server Error');
+	my %http_responses = (
+		400 => '400 Bad Request',
+		403 => '403 Forbidden',
+		404 => '404 Not Found',
+		500 => '500 Internal Server Error',
+		503 => '503 Service Unavailable',
+	);
 	git_header_html($http_responses{$status});
 	print <<EOF;
 <div class="page_body">