4 files changed, 72 insertions, 14 deletions

diff --git a/source/ui-empty.c b/source/ui-empty.c
index a65f49b..dd8dc64 100644
--- a/source/ui-empty.c
+++ b/source/ui-empty.c
@@ -13,13 +13,7 @@
 
 static void print_clone_url(const char *url)
 {
-	html("<tr><td class='clone-url'><a rel='vcs-git' href='");
-	html_url_path(url);
-	html("' title='");
-	html_attr(ctx.repo->name);
-	html(" Git repository'>");
-	html_txt(url);
-	html("</a></td></tr>\n");
+	cgit_print_clone_row(url, 0);
 }
 
 /*
diff --git a/source/ui-shared.c b/source/ui-shared.c
index 85712bf..5cf9428 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -317,8 +317,26 @@ static void print_rel_date(time_t t, int tz, double count, const char *class,
 	htmlf("'>%.0f %s</time>", count, suffix);
 }
 
+/*
+ * Whether a clone url opens with a URI scheme. The scp form git@host:path
+ * has none, and a link element's href must hold a URI, so that form stays
+ * out of the document head.
+ */
+static int has_uri_scheme(const char *url)
+{
+	const char *p = url;
+
+	if (!isalpha((unsigned char)*p))
+		return 0;
+	while (isalnum((unsigned char)*p) || *p == '+' || *p == '-' || *p == '.')
+		p++;
+	return *p == ':';
+}
+
 static void print_rel_vcs_link(const char *url)
 {
+	if (!has_uri_scheme(url))
+		return;
 	html("<link rel='vcs-git' href='");
 	html_attr(url);
 	html("' title='");
@@ -1620,6 +1638,57 @@ void cgit_add_clone_urls(void (*fn)(const char *))
 		add_clone_urls(fn, ctx.cfg.clone_prefix, ctx.repo->url);
 }
 
+static char *http_clone_url;
+static int http_clone_url_scanned;
+
+// Scheme names compare case-insensitively.
+static int is_http_url(const char *url)
+{
+	return istarts_with(url, "http://") || istarts_with(url, "https://");
+}
+
+static void capture_http_clone_url(const char *url)
+{
+	if (!http_clone_url && is_http_url(url))
+		http_clone_url = xstrdup(url);
+}
+
+/*
+ * One row of the clone table. The url is shown as written, and every row is
+ * a link, but a browser cannot follow the ssh, scp or git forms, so those
+ * rows point at the first http url in the clone list, or at the repository's
+ * own page when the list has none, which with http clone enabled is itself a
+ * working clone url. A colspan of zero leaves the attribute out.
+ */
+void cgit_print_clone_row(const char *url, int colspan)
+{
+	const char *href = url;
+	char *fallback = NULL;
+
+	if (!is_http_url(url)) {
+		if (!http_clone_url_scanned) {
+			http_clone_url_scanned = 1;
+			cgit_add_clone_urls(capture_http_clone_url);
+		}
+		href = http_clone_url;
+		if (!href)
+			href = fallback = cgit_repourl(ctx.repo->url);
+	}
+
+	if (colspan)
+		htmlf("<tr><td colspan='%d' class='clone-url'>", colspan);
+	else
+		html("<tr><td class='clone-url'>");
+	html("<a rel='vcs-git' title='");
+	html_attr(ctx.repo->name);
+	html(" Git repository' href='");
+	html_attr(href);
+	html("'>");
+	html_txt(url);
+	html("</a></td></tr>\n");
+	free(fallback);
+}
+
 void cgit_add_hidden_formfields(int incl_head, int incl_search,
 				const char *page)
 {
diff --git a/source/ui-shared.h b/source/ui-shared.h
index c266951..c421178 100644
--- a/source/ui-shared.h
+++ b/source/ui-shared.h
@@ -24,6 +24,7 @@ extern char *cgit_currenturl(void);
 extern char *cgit_currentfullurl(void);
 extern const char *cgit_loginurl(void);
 extern char *cgit_repourl(const char *reponame);
+extern void cgit_print_clone_row(const char *url, int colspan);
 extern char *cgit_fileurl(const char *reponame, const char *pagename,
 			  const char *filename, const char *query);
 extern char *cgit_pageurl(const char *reponame, const char *pagename,
diff --git a/source/ui-summary.c b/source/ui-summary.c
index 3658bc5..dacf0f7 100644
--- a/source/ui-summary.c
+++ b/source/ui-summary.c
@@ -48,13 +48,7 @@ static void print_clone_url(const char *url)
 		htmlf("<tr class='nohover'><th colspan='%d' class='left'>Clone</th></tr>\n", columns);
 	}
 
-	htmlf("<tr><td colspan='%d' class='clone-url'><a rel='vcs-git' href='", columns);
-	html_url_path(url);
-	html("' title='");
-	html_attr(ctx.repo->name);
-	html(" Git repository'>");
-	html_txt(url);
-	html("</a></td></tr>\n");
+	cgit_print_clone_row(url, columns);
 }
 
 /*