ui-commit: add support for 'commit-filter' option

This new option specifies a filter which is executed on the commit
message, i.e. the commit message is written to the filters STDIN and
the filters STDOUT is included verbatim as the commit message.

This can be used to implement commit linking by creating a simple
shell script in e.g. /usr/bin/cgit-commit-filter.sh like this:

#/bin/sh
sed -re 's|\b([0-9a-fA-F]{6,40})\b|<a href="./?id=\1">\1</a>|g'

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

4 files changed, 17 insertions, 0 deletions

diff --git a/cgit.c b/cgit.c
index eb7b45d..2cda554 100644
--- a/cgit.c
+++ b/cgit.c
@@ -87,12 +87,14 @@ void config_cb(const char *name, const char *value)
         else if (!strcmp(name, "cache-repo-ttl"))
                 ctx.cfg.cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 ctx.cfg.cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 ctx.cfg.cache_dynamic_ttl = atoi(value);
+        else if (!strcmp(name, "commit-filter"))
+                ctx.cfg.commit_filter = new_filter(value, 0);
         else if (!strcmp(name, "embedded"))
                 ctx.cfg.embedded = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 ctx.cfg.max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 ctx.cfg.max_repodesc_len = atoi(value);
diff --git a/cgit.h b/cgit.h
index f9cf0df..438301d 100644
--- a/cgit.h
+++ b/cgit.h
@@ -180,12 +180,13 @@ struct cgit_config {
         int noheader;
         int renamelimit;
         int snapshots;
         int summary_branches;
         int summary_log;
         int summary_tags;
+        struct cgit_filter *commit_filter;
         struct cgit_filter *source_filter;
 };
 
 struct cgit_page {
         time_t modified;
         time_t expires;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index d420ad4..2efd6aa 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -52,12 +52,18 @@ cache-static-ttl::
 clone-prefix::
         Space-separated list of common prefixes which, when combined with a
         repository url, generates valid clone urls for the repository. This
         setting is only used if `repo.clone-url` is unspecified. Default value:
         none.
 
+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
+        command will be included verbatim as the commit message, i.e. this can
+        be used to implement bugtracker integration. Default value: none.
+
 css::
         Url which specifies the css document to include in all cgit pages.
         Default value: "/cgit.css".
 
 embedded::
         Flag which, when set to "1", will make cgit generate a html fragment
diff --git a/ui-commit.c b/ui-commit.c
index 41ce70e..ee0e139 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -86,17 +86,25 @@ void cgit_print_commit(char *hex)
                 cgit_print_snapshot_links(ctx.qry.repo, ctx.qry.head,
                                           hex, ctx.repo->snapshots);
                 html("</td></tr>");
         }
         html("</table>\n");
         html("<div class='commit-subject'>");
+        if (ctx.cfg.commit_filter)
+                cgit_open_filter(ctx.cfg.commit_filter);
         html_txt(info->subject);
+        if (ctx.cfg.commit_filter)
+                cgit_close_filter(ctx.cfg.commit_filter);
         show_commit_decorations(commit);
         html("</div>");
         html("<div class='commit-msg'>");
+        if (ctx.cfg.commit_filter)
+                cgit_open_filter(ctx.cfg.commit_filter);
         html_txt(info->msg);
+        if (ctx.cfg.commit_filter)
+                cgit_close_filter(ctx.cfg.commit_filter);
         html("</div>");
         if (parents < 3) {
                 if (parents)
                         tmp = sha1_to_hex(commit->parents->item->object.sha1);
                 else
                         tmp = NULL;