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
@@ -182,6 +182,8 @@ void config_cb(const char *name, const char *value)
                 ctx.cfg.summary_branches = atoi(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);
         else if (!strcmp(name, "renamelimit"))
@@ -238,6 +240,8 @@ static void querystring_cb(const char *name, const char *value)
                 ctx.qry.showmsg = atoi(value);
         } else if (!strcmp(name, "period")) {
                 ctx.qry.period = xstrdup(value);
+        } else if (!strcmp(name, "ss")) {
+                ctx.qry.ssdiff = atoi(value);
         }
 }
 
@@ -279,6 +283,7 @@ static void prepare_context(struct cgit_context *ctx)
         ctx->cfg.summary_branches = 10;
         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"));
         ctx->env.https = xstrdupn(getenv("HTTPS"));
diff --git a/cgit.h b/cgit.h
index 6c6c460..b7b0adb 100644
--- a/cgit.h
+++ b/cgit.h
@@ -143,6 +143,7 @@ struct cgit_query {
         int nohead;
         char *sort;
         int showmsg;
+        int ssdiff;
 };
 
 struct cgit_config {
@@ -194,6 +195,7 @@ struct cgit_config {
         int summary_branches;
         int summary_log;
         int summary_tags;
+        int ssdiff;
         struct string_list mimetypes;
         struct cgit_filter *about_filter;
         struct cgit_filter *commit_filter;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 4dc383d..252d546 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -238,6 +238,10 @@ section::
         after this option will inherit the current section name. Default value:
         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
         cgit. The value is a space-separated list of zero or more of the
diff --git a/ui-commit.c b/ui-commit.c
index f5b0ae5..b5e3c01 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -58,9 +58,14 @@ void cgit_print_commit(char *hex)
         html("</td></tr>\n");
         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'>");
         tmp = xstrdup(hex);
@@ -78,10 +83,10 @@ void cgit_print_commit(char *hex)
                 html("<tr><th>parent</th>"
                      "<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
@@ -85,7 +85,7 @@ 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)",
                       info->status == DIFF_STATUS_COPIED ? "copied" : "renamed",
@@ -160,7 +160,7 @@ 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'>");
         max_changes = 0;
@@ -250,6 +250,19 @@ static void header(unsigned char *sha1, char *path1, int mode1,
                 cgit_ssdiff_header();
 }
 
+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)
 {
         unsigned long old_size = 0;
@@ -314,6 +327,11 @@ void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefi
                 if (!commit2 || parse_commit(commit2))
                         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);
 
         html("<table summary='diff' class='diff'>");
diff --git a/ui-log.c b/ui-log.c
index f3132c9..0947604 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -66,7 +66,7 @@ void show_commit_decorations(struct commit *commit)
                 else {
                         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;
         }
@@ -89,7 +89,7 @@ void print_commit(struct commit *commit)
         htmlf("</td><td%s>",
                 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>");
         html_txt(info->author);
diff --git a/ui-refs.c b/ui-refs.c
index d3b4f6e..33d9bec 100644
--- a/ui-refs.c
+++ b/ui-refs.c
@@ -74,7 +74,7 @@ static int print_branch(struct refinfo *ref)
         html("</td><td>");
 
         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);
                 html("</td><td colspan='2'>");
diff --git a/ui-shared.c b/ui-shared.c
index 07d5dd4..de55eff 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -317,7 +317,7 @@ 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) {
                 name[ctx.cfg.max_msg_len] = '\0';
@@ -325,7 +325,23 @@ void cgit_commit_link(char *name, char *title, char *class, char *head,
                 name[ctx.cfg.max_msg_len - 2] = '.';
                 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>");
 }
 
 void cgit_refs_link(char *name, char *title, char *class, char *head,
@@ -341,7 +357,8 @@ 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;
 
@@ -356,6 +373,11 @@ void cgit_diff_link(char *name, char *title, char *class, char *head,
                 html(delim);
                 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("'>");
         html_txt(name);
@@ -383,7 +405,7 @@ void cgit_object_link(struct object *obj)
         shortrev[10] = '\0';
         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)
                 page = "tree";
@@ -695,9 +717,9 @@ void cgit_print_pageheader(struct cgit_context *ctx)
                 cgit_tree_link("tree", NULL, hc(cmd, "tree"), ctx->qry.head,
                                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"),
                                         ctx->qry.head, NULL);
diff --git a/ui-shared.h b/ui-shared.h
index bff4826..166246d 100644
--- a/ui-shared.h
+++ b/ui-shared.h
@@ -22,7 +22,7 @@ extern void cgit_log_link(char *name, char *title, char *class, char *head,
                           char *rev, char *path, int ofs, char *grep,
                           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);
 extern void cgit_refs_link(char *name, char *title, char *class, char *head,
@@ -30,7 +30,8 @@ extern void cgit_refs_link(char *name, char *title, char *class, char *head,
 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);
 extern void cgit_object_link(struct object *obj);