Add possibility to switch between unidiff and side-by-side-diff.

A new config option side-by-side-diffs added, defaulting to 0,
meaning unidiff. Also a query option (ss) is used toggle this.

In the commit page you can switch between the two diff formats by
clicking on the link on the "commit"-row, to the right of (patch).

In the diff page you can switch by using the link at the start
of the page.

All commit-links and diff-links will remember the choice.

Signed-off-by: Ragnar Ouchterlony <ragnar@lysator.liu.se>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

9 files changed, 73 insertions, 16 deletions

diff --git a/cgit.c b/cgit.c
index bd37788..ff678fb 100644
--- a/cgit.c
+++ b/cgit.c
@@ -183,4 +183,6 @@ void config_cb(const char *name, const char *value)
 	else if (!strcmp(name, "summary-tags"))
 		ctx.cfg.summary_tags = atoi(value);
+	else if (!strcmp(name, "side-by-side-diffs"))
+		ctx.cfg.ssdiff = atoi(value);
 	else if (!strcmp(name, "agefile"))
 		ctx.cfg.agefile = xstrdup(value);
@@ -239,4 +241,6 @@ static void querystring_cb(const char *name, const char *value)
 	} else if (!strcmp(name, "period")) {
 		ctx.qry.period = xstrdup(value);
+	} else if (!strcmp(name, "ss")) {
+		ctx.qry.ssdiff = atoi(value);
 	}
 }
@@ -280,4 +284,5 @@ static void prepare_context(struct cgit_context *ctx)
 	ctx->cfg.summary_log = 10;
 	ctx->cfg.summary_tags = 10;
+	ctx->cfg.ssdiff = 0;
 	ctx->env.cgit_config = xstrdupn(getenv("CGIT_CONFIG"));
 	ctx->env.http_host = xstrdupn(getenv("HTTP_HOST"));
diff --git a/cgit.h b/cgit.h
index 6c6c460..b7b0adb 100644
--- a/cgit.h
+++ b/cgit.h
@@ -144,4 +144,5 @@ struct cgit_query {
 	char *sort;
 	int showmsg;
+	int ssdiff;
 };
 
@@ -195,4 +196,5 @@ struct cgit_config {
 	int summary_log;
 	int summary_tags;
+	int ssdiff;
 	struct string_list mimetypes;
 	struct cgit_filter *about_filter;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 4dc383d..252d546 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -239,4 +239,8 @@ section::
 	none.
 
+side-by-side-diffs::
+	If set to "1" shows side-by-side diffs instead of unidiffs per
+	default. Default value: "0".
+
 snapshots::
 	Text which specifies the default set of snapshot formats generated by
diff --git a/ui-commit.c b/ui-commit.c
index f5b0ae5..b5e3c01 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -59,7 +59,12 @@ void cgit_print_commit(char *hex)
 	html("<tr><th>commit</th><td colspan='2' class='sha1'>");
 	tmp = sha1_to_hex(commit->object.sha1);
-	cgit_commit_link(tmp, NULL, NULL, ctx.qry.head, tmp);
+	cgit_commit_link(tmp, NULL, NULL, ctx.qry.head, tmp, 0);
 	html(" (");
 	cgit_patch_link("patch", NULL, NULL, NULL, tmp);
+	html(") (");
+	if ((ctx.qry.ssdiff && !ctx.cfg.ssdiff) || (!ctx.qry.ssdiff && ctx.cfg.ssdiff))
+		cgit_commit_link("unidiff", NULL, NULL, ctx.qry.head, tmp, 1);
+	else
+		cgit_commit_link("side-by-side diff", NULL, NULL, ctx.qry.head, tmp, 1);
 	html(")</td></tr>\n");
 	html("<tr><th>tree</th><td colspan='2' class='sha1'>");
@@ -79,8 +84,8 @@ void cgit_print_commit(char *hex)
 		     "<td colspan='2' class='sha1'>");
 		cgit_commit_link(sha1_to_hex(p->item->object.sha1), NULL, NULL,
-				 ctx.qry.head, sha1_to_hex(p->item->object.sha1));
+				 ctx.qry.head, sha1_to_hex(p->item->object.sha1), 0);
 		html(" (");
 		cgit_diff_link("diff", NULL, NULL, ctx.qry.head, hex,
-			       sha1_to_hex(p->item->object.sha1), NULL);
+			       sha1_to_hex(p->item->object.sha1), NULL, 0);
 		html(")</td></tr>");
 		parents++;
diff --git a/ui-diff.c b/ui-diff.c
index 0c6f8d7..42e81ac 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -86,5 +86,5 @@ static void print_fileinfo(struct fileinfo *info)
 	htmlf("</td><td class='%s'>", class);
 	cgit_diff_link(info->new_path, NULL, NULL, ctx.qry.head, ctx.qry.sha1,
-		       ctx.qry.sha2, info->new_path);
+		       ctx.qry.sha2, info->new_path, 0);
 	if (info->status == DIFF_STATUS_COPIED || info->status == DIFF_STATUS_RENAMED)
 		htmlf(" (%s from %s)",
@@ -161,5 +161,5 @@ void cgit_print_diffstat(const unsigned char *old_sha1,
 	html("<div class='diffstat-header'>");
 	cgit_diff_link("Diffstat", NULL, NULL, ctx.qry.head, ctx.qry.sha1,
-		       ctx.qry.sha2, NULL);
+		       ctx.qry.sha2, NULL, 0);
 	html("</div>");
 	html("<table summary='diffstat' class='diffstat'>");
@@ -251,4 +251,17 @@ static void header(unsigned char *sha1, char *path1, int mode1,
 }
 
+static void print_ssdiff_link()
+{
+	if (!strcmp(ctx.qry.page, "diff")) {
+		if (use_ssdiff)
+			cgit_diff_link("Unidiff", NULL, NULL, ctx.qry.head,
+				       ctx.qry.sha1, ctx.qry.sha2, NULL, 1);
+		else
+			cgit_diff_link("Side-by-side diff", NULL, NULL,
+				       ctx.qry.head, ctx.qry.sha1,
+				       ctx.qry.sha2, NULL, 1);
+	}
+}
+
 static void filepair_cb(struct diff_filepair *pair)
 {
@@ -315,4 +328,9 @@ void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefi
 			cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(old_rev_sha1)));
 	}
+
+	if ((ctx.qry.ssdiff && !ctx.cfg.ssdiff) || (!ctx.qry.ssdiff && ctx.cfg.ssdiff))
+		use_ssdiff = 1;
+
+	print_ssdiff_link();
 	cgit_print_diffstat(old_rev_sha1, new_rev_sha1);
 
diff --git a/ui-log.c b/ui-log.c
index f3132c9..0947604 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -67,5 +67,5 @@ void show_commit_decorations(struct commit *commit)
 			strncpy(buf, deco->name, sizeof(buf) - 1);
 			cgit_commit_link(buf, NULL, "deco", ctx.qry.head,
-				sha1_to_hex(commit->object.sha1));
+				sha1_to_hex(commit->object.sha1), 0);
 		}
 		deco = deco->next;
@@ -90,5 +90,5 @@ void print_commit(struct commit *commit)
 		ctx.qry.showmsg ? " class='logsubject'" : "");
 	cgit_commit_link(info->subject, NULL, NULL, ctx.qry.head,
-			 sha1_to_hex(commit->object.sha1));
+			 sha1_to_hex(commit->object.sha1), 0);
 	show_commit_decorations(commit);
 	html("</td><td>");
diff --git a/ui-refs.c b/ui-refs.c
index d3b4f6e..33d9bec 100644
--- a/ui-refs.c
+++ b/ui-refs.c
@@ -75,5 +75,5 @@ static int print_branch(struct refinfo *ref)
 
 	if (ref->object->type == OBJ_COMMIT) {
-		cgit_commit_link(info->subject, NULL, NULL, name, NULL);
+		cgit_commit_link(info->subject, NULL, NULL, name, NULL, 0);
 		html("</td><td>");
 		html_txt(info->author);
diff --git a/ui-shared.c b/ui-shared.c
index 07d5dd4..de55eff 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -318,5 +318,5 @@ void cgit_log_link(char *name, char *title, char *class, char *head,
 
 void cgit_commit_link(char *name, char *title, char *class, char *head,
-		      char *rev)
+		      char *rev, int toggle_ssdiff)
 {
 	if (strlen(name) > ctx.cfg.max_msg_len && ctx.cfg.max_msg_len >= 15) {
@@ -326,5 +326,21 @@ void cgit_commit_link(char *name, char *title, char *class, char *head,
 		name[ctx.cfg.max_msg_len - 3] = '.';
 	}
-	reporevlink("commit", name, title, class, head, rev, NULL);
+
+	char *delim;
+
+	delim = repolink(title, class, "commit", head, NULL);
+	if (rev && strcmp(rev, ctx.qry.head)) {
+		html(delim);
+		html("id=");
+		html_url_arg(rev);
+		delim = "&amp;";
+	}
+	if ((ctx.qry.ssdiff && !toggle_ssdiff) || (!ctx.qry.ssdiff && toggle_ssdiff)) {
+		html(delim);
+		html("ss=1");
+	}
+	html("'>");
+	html_txt(name);
+	html("</a>");
 }
 
@@ -342,5 +358,6 @@ void cgit_snapshot_link(char *name, char *title, char *class, char *head,
 
 void cgit_diff_link(char *name, char *title, char *class, char *head,
-		    char *new_rev, char *old_rev, char *path)
+		    char *new_rev, char *old_rev, char *path,
+		    int toggle_ssdiff)
 {
 	char *delim;
@@ -357,4 +374,9 @@ void cgit_diff_link(char *name, char *title, char *class, char *head,
 		html("id2=");
 		html_url_arg(old_rev);
+		delim = "&amp;";
+	}
+	if ((ctx.qry.ssdiff && !toggle_ssdiff) || (!ctx.qry.ssdiff && toggle_ssdiff)) {
+		html(delim);
+		html("ss=1");
 	}
 	html("'>");
@@ -384,5 +406,5 @@ void cgit_object_link(struct object *obj)
 	if (obj->type == OBJ_COMMIT) {
                 cgit_commit_link(fmt("commit %s...", shortrev), NULL, NULL,
-				 ctx.qry.head, fullrev);
+				 ctx.qry.head, fullrev, 0);
 		return;
 	} else if (obj->type == OBJ_TREE)
@@ -696,7 +718,7 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 			       ctx->qry.sha1, NULL);
 		cgit_commit_link("commit", NULL, hc(cmd, "commit"),
-				 ctx->qry.head, ctx->qry.sha1);
+				 ctx->qry.head, ctx->qry.sha1, 0);
 		cgit_diff_link("diff", NULL, hc(cmd, "diff"), ctx->qry.head,
-			       ctx->qry.sha1, ctx->qry.sha2, NULL);
+			       ctx->qry.sha1, ctx->qry.sha2, NULL, 0);
 		if (ctx->repo->max_stats)
 			cgit_stats_link("stats", NULL, hc(cmd, "stats"),
diff --git a/ui-shared.h b/ui-shared.h
index bff4826..166246d 100644
--- a/ui-shared.h
+++ b/ui-shared.h
@@ -23,5 +23,5 @@ extern void cgit_log_link(char *name, char *title, char *class, char *head,
 			  char *pattern, int showmsg);
 extern void cgit_commit_link(char *name, char *title, char *class, char *head,
-			     char *rev);
+			     char *rev, int toggle_ssdiff);
 extern void cgit_patch_link(char *name, char *title, char *class, char *head,
 			    char *rev);
@@ -31,5 +31,6 @@ extern void cgit_snapshot_link(char *name, char *title, char *class,
 			       char *head, char *rev, char *archivename);
 extern void cgit_diff_link(char *name, char *title, char *class, char *head,
-			   char *new_rev, char *old_rev, char *path);
+			   char *new_rev, char *old_rev, char *path,
+			   int toggle_ssdiff);
 extern void cgit_stats_link(char *name, char *title, char *class, char *head,
 			    char *path);