cgit.c: add 'clone-url' setting with support for macro expansion

The current 'clone-prefix' setting has some known issues:
* All repos get the same 'clone-prefix' value since the setting is not
  adopted during repo registration (in cgitrc, or during scan-path traversal),
  but only when the setting is used.
* The generated clone-urls for a repo is a combination of 'clone-prefix', a
  slash and the repo url. This doesn't work well with e.g. ssh-style urls
  like 'git@example.org:repo.git', since the inserted slash will make the
  repo relative to the filesystem root.
* If 'remove-suffix' is enabled, the generated clone-urls will not work for
  cloning (except for http-urls to cgit itself) since they miss the '.git'
  suffix.

The new 'clone-url' setting is designed to avoid the mentioned issues:
* Each repo adopts the default 'clone-url' when the repo is defined. This
  allows different groups of repos to adopt different values.
* The clone-urls for a repo is generated by expanding environment variables
  in a string template without inserting arbitrary characters, hence any
  kind of clone-url can be generated.
* Macro expansion also eases the 'remove-suffix' pain since it's now
  possible to define e.g. 'clone-url=git://foo.org/$CGIT_REPO_URL.git' for
  a set of repos. A furter improvement would be to define e.g.
  $CGIT_REPO_SUFFIX to '.git' for all repos which had their url prettified,
  or to store the original $CGIT_REPO_URL in e.g. $CGIT_REPO_REAL_URL before
  suffix removal.

Reviewed-by: Ferry Huberts <mailings@hupie.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.c

@@ -244,6 +244,8 @@ void config_cb(const char *name, const char *value)
 		ctx.cfg.robots = xstrdup(value);
 	else if (!strcmp(name, "clone-prefix"))
 		ctx.cfg.clone_prefix = xstrdup(value);
+	else if (!strcmp(name, "clone-url"))
+		ctx.cfg.clone_url = xstrdup(value);
 	else if (!strcmp(name, "local-time"))
 		ctx.cfg.local_time = atoi(value);
 	else if (!prefixcmp(name, "mimetype."))

cgit.h

@@ -165,6 +165,7 @@ struct cgit_config {
 	char *agefile;
 	char *cache_root;
 	char *clone_prefix;
+	char *clone_url;
 	char *css;
 	char *favicon;
 	char *footer;

cgitrc.5.txt

@@ -76,6 +76,11 @@ clone-prefix::
 	setting is only used if `repo.clone-url` is unspecified. Default value:
 	none.
 
+clone-url::
+	Space-separated list of clone-url templates. This setting is only
+	used if `repo.clone-url` is unspecified. Default value: none. See
+	also: "MACRO EXPANSION", "FILTER API".
+
 commit-filter::
 	Specifies a command which will be invoked to format commit messages.
 	The command will get the message on its STDIN, and the STDOUT from the
@@ -363,7 +368,7 @@ repo.about-filter::
 
 repo.clone-url::
 	A list of space-separated urls which can be used to clone this repo.
-	Default value: none.
+	Default value: none. See also: "MACRO EXPANSION".
 
 repo.commit-filter::
 	Override the default commit-filter. Default value: none. See also:
@@ -511,6 +516,12 @@ can be accomplished by adding the following line to /etc/cgitrc:
 
 	include=/etc/cgitrc.d/$HTTP_HOST
 
+The following options are expanded during request processing, and support
+the environment variables defined in "FILTER API":
+
+- clone-url
+- repo.clone-url
+
 
 EXAMPLE CGITRC FILE
 -------------------
@@ -520,8 +531,8 @@ EXAMPLE CGITRC FILE
 cache-size=1000
 
 
-# Specify some default clone prefixes
+# Specify some default clone urls using macro expansion
-clone-prefix=git://example.com ssh://example.com/pub/git http://example.com/git
+clone-url=git://foo.org/$CGIT_REPO_URL git@foo.org:$CGIT_REPO_URL
 
 # Specify the css url
 css=/css/cgit.css

shared.c

@@ -70,6 +70,7 @@ struct cgit_repo *cgit_add_repo(const char *url)
 	ret->about_filter = ctx.cfg.about_filter;
 	ret->commit_filter = ctx.cfg.commit_filter;
 	ret->source_filter = ctx.cfg.source_filter;
+	ret->clone_url = ctx.cfg.clone_url;
 	return ret;
 }
 

tests/setup.sh

@@ -62,6 +62,7 @@ enable-log-linecount=1
 summary-log=5
 summary-branches=5
 summary-tags=5
+clone-url=git://example.org/\$CGIT_REPO_URL.git
 
 repo.url=foo
 repo.path=$PWD/trash/repos/foo/.git

tests/t0102-summary.sh

@@ -9,6 +9,9 @@ run_test 'find commit 1' 'grep -e "commit 1" trash/tmp'
 run_test 'find commit 5' 'grep -e "commit 5" trash/tmp'
 run_test 'find branch master' 'grep -e "master" trash/tmp'
 run_test 'no tags' '! grep -e "tags" trash/tmp'
+run_test 'clone-url expanded correctly' '
+	grep -e "git://example.org/foo.git" trash/tmp
+'
 
 run_test 'generate bar summary' 'cgit_url "bar" >trash/tmp'
 run_test 'no commit 45' '! grep -e "commit 45" trash/tmp'
@@ -16,5 +19,8 @@ run_test 'find commit 46' 'grep -e "commit 46" trash/tmp'
 run_test 'find commit 50' 'grep -e "commit 50" trash/tmp'
 run_test 'find branch master' 'grep -e "master" trash/tmp'
 run_test 'no tags' '! grep -e "tags" trash/tmp'
+run_test 'clone-url expanded correctly' '
+	grep -e "git://example.org/bar.git" trash/tmp
+'
 
 tests_done

ui-summary.c

@@ -62,7 +62,7 @@ void cgit_print_summary()
 			       NULL, NULL, 0, 0);
 	}
 	if (ctx.repo->clone_url)
-		print_urls(ctx.repo->clone_url, NULL);
+		print_urls(expand_macros(ctx.repo->clone_url), NULL);
 	else if (ctx.cfg.clone_prefix)
 		print_urls(ctx.cfg.clone_prefix, ctx.repo->url);
 	html("</table>");