1 files changed, 310 insertions, 98 deletions

diff --git a/ui-diff.c b/ui-diff.c
index e0a72f7..5ee3830 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -1,18 +1,25 @@
 /* ui-diff.c: show diff between two blobs
  *
- * Copyright (C) 2006 Lars Hjemli
+ * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
+ * Copyright (C) 2026 Saya Andy <saya.andy@posteo.com>
+ *
+ * Modified 2026 by Saya Andy:
+ *   Select variable refs from web ui for diff
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "cgit.h"
+#include "ui-diff.h"
 #include "html.h"
 #include "ui-shared.h"
 #include "ui-ssdiff.h"
 
-unsigned char old_rev_sha1[20];
-unsigned char new_rev_sha1[20];
+struct object_id old_rev_oid[1];
+struct object_id new_rev_oid[1];
 
 static int files, slots;
 static int total_adds, total_rems, max_changes;
@@ -20,8 +27,8 @@ static int lines_added, lines_removed;
 
 static struct fileinfo {
 	char status;
-	unsigned char old_sha1[20];
-	unsigned char new_sha1[20];
+	struct object_id old_oid[1];
+	struct object_id new_oid[1];
 	unsigned short old_mode;
 	unsigned short new_mode;
 	char *old_path;
@@ -30,10 +37,22 @@ static struct fileinfo {
 	unsigned int removed;
 	unsigned long old_size;
 	unsigned long new_size;
-	int binary:1;
+	unsigned int binary:1;
 } *items;
 
 static int use_ssdiff = 0;
+static struct diff_filepair *current_filepair;
+static const char *current_prefix;
+
+struct diff_filespec *cgit_get_current_old_file(void)
+{
+	return current_filepair->one;
+}
+
+struct diff_filespec *cgit_get_current_new_file(void)
+{
+	return current_filepair->two;
+}
 
 static void print_fileinfo(struct fileinfo *info)
 {
@@ -69,30 +88,32 @@ static void print_fileinfo(struct fileinfo *info)
 	}
 
 	html("<tr>");
-	htmlf("<td class='mode'>");
-	if (is_null_sha1(info->new_sha1)) {
+	html("<td class='mode'>");
+	if (is_null_oid(info->new_oid)) {
 		cgit_print_filemode(info->old_mode);
 	} else {
 		cgit_print_filemode(info->new_mode);
 	}
 
 	if (info->old_mode != info->new_mode &&
-	    !is_null_sha1(info->old_sha1) &&
-	    !is_null_sha1(info->new_sha1)) {
+	    !is_null_oid(info->old_oid) &&
+	    !is_null_oid(info->new_oid)) {
 		html("<span class='modechange'>[");
 		cgit_print_filemode(info->old_mode);
 		html("]</span>");
 	}
 	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, 0);
-	if (info->status == DIFF_STATUS_COPIED || info->status == DIFF_STATUS_RENAMED)
-		htmlf(" (%s from %s)",
-		      info->status == DIFF_STATUS_COPIED ? "copied" : "renamed",
-		      info->old_path);
+	cgit_diff_link(info->new_path, NULL, NULL, ctx.qry.head, ctx.qry.oid,
+		       ctx.qry.oid2, info->new_path);
+	if (info->status == DIFF_STATUS_COPIED || info->status == DIFF_STATUS_RENAMED) {
+		htmlf(" (%s from ",
+		      info->status == DIFF_STATUS_COPIED ? "copied" : "renamed");
+		html_txt(info->old_path);
+		html(")");
+	}
 	html("</td><td class='right'>");
 	if (info->binary) {
-		htmlf("bin</td><td class='graph'>%d -> %d bytes",
+		htmlf("bin</td><td class='graph'>%ld -> %ld bytes",
 		      info->old_size, info->new_size);
 		return;
 	}
@@ -118,16 +139,35 @@ static void count_diff_lines(char *line, int len)
 	}
 }
 
+static int show_filepair(struct diff_filepair *pair)
+{
+	/* Always show if we have no limiting prefix. */
+	if (!current_prefix)
+		return 1;
+
+	/* Show if either path in the pair begins with the prefix. */
+	if (starts_with(pair->one->path, current_prefix) ||
+	    starts_with(pair->two->path, current_prefix))
+		return 1;
+
+	/* Otherwise we don't want to show this filepair. */
+	return 0;
+}
+
 static void inspect_filepair(struct diff_filepair *pair)
 {
 	int binary = 0;
 	unsigned long old_size = 0;
 	unsigned long new_size = 0;
+
+	if (!show_filepair(pair))
+		return;
+
 	files++;
 	lines_added = 0;
 	lines_removed = 0;
-	cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size, &new_size,
-			&binary, 0, count_diff_lines);
+	cgit_diff_files(&pair->one->oid, &pair->two->oid, &old_size, &new_size,
+			&binary, 0, ctx.qry.ignorews, count_diff_lines);
 	if (files >= slots) {
 		if (slots == 0)
 			slots = 4;
@@ -136,8 +176,8 @@ static void inspect_filepair(struct diff_filepair *pair)
 		items = xrealloc(items, slots * sizeof(struct fileinfo));
 	}
 	items[files-1].status = pair->status;
-	hashcpy(items[files-1].old_sha1, pair->one->sha1);
-	hashcpy(items[files-1].new_sha1, pair->two->sha1);
+	oidcpy(items[files-1].old_oid, &pair->one->oid);
+	oidcpy(items[files-1].new_oid, &pair->two->oid);
 	items[files-1].old_mode = pair->one->mode;
 	items[files-1].new_mode = pair->two->mode;
 	items[files-1].old_path = xstrdup(pair->one->path);
@@ -153,29 +193,26 @@ static void inspect_filepair(struct diff_filepair *pair)
 	total_rems += lines_removed;
 }
 
-void cgit_print_diffstat(const unsigned char *old_sha1,
-			 const unsigned char *new_sha1, const char *prefix)
+static void cgit_print_diffstat(const struct object_id *old_oid,
+				const struct object_id *new_oid,
+				const char *prefix)
 {
-	int i, save_context = ctx.qry.context;
+	int i;
 
 	html("<div class='diffstat-header'>");
-	cgit_diff_link("Diffstat", NULL, NULL, ctx.qry.head, ctx.qry.sha1,
-		       ctx.qry.sha2, NULL, 0);
-	if (prefix)
-		htmlf(" (limited to '%s')", prefix);
-	html(" (");
-	ctx.qry.context = (save_context > 0 ? save_context : 3) << 1;
-	cgit_self_link("more", NULL, NULL, &ctx);
-	html("/");
-	ctx.qry.context = (save_context > 3 ? save_context : 3) >> 1;
-	cgit_self_link("less", NULL, NULL, &ctx);
-	ctx.qry.context = save_context;
-	html(" context)");
+	cgit_diff_link("Diffstat", NULL, NULL, ctx.qry.head, ctx.qry.oid,
+		       ctx.qry.oid2, NULL);
+	if (prefix) {
+		html(" (limited to '");
+		html_txt(prefix);
+		html("')");
+	}
 	html("</div>");
 	html("<table summary='diffstat' class='diffstat'>");
 	max_changes = 0;
-	cgit_diff_tree(old_sha1, new_sha1, inspect_filepair, prefix);
-	for(i = 0; i<files; i++)
+	cgit_diff_tree(old_oid, new_oid, inspect_filepair, prefix,
+		       ctx.qry.ignorews);
+	for (i = 0; i<files; i++)
 		print_fileinfo(&items[i]);
 	html("</table>");
 	html("<div class='diffstat-summary'>");
@@ -207,8 +244,8 @@ static void print_line(char *line, int len)
 	line[len-1] = c;
 }
 
-static void header(unsigned char *sha1, char *path1, int mode1,
-		   unsigned char *sha2, char *path2, int mode2)
+static void header(const struct object_id *oid1, char *path1, int mode1,
+		   const struct object_id *oid2, char *path2, int mode2)
 {
 	char *abbrev1, *abbrev2;
 	int subproject;
@@ -220,11 +257,6 @@ static void header(unsigned char *sha1, char *path1, int mode1,
 	html(" b/");
 	html_txt(path2);
 
-	if (is_null_sha1(sha1))
-		path1 = "dev/null";
-	if (is_null_sha1(sha2))
-		path2 = "dev/null";
-
 	if (mode1 == 0)
 		htmlf("<br/>new file mode %.6o", mode2);
 
@@ -232,8 +264,8 @@ static void header(unsigned char *sha1, char *path1, int mode1,
 		htmlf("<br/>deleted file mode %.6o", mode1);
 
 	if (!subproject) {
-		abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
-		abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
+		abbrev1 = xstrdup(repo_find_unique_abbrev(the_repository, oid1, DEFAULT_ABBREV));
+		abbrev2 = xstrdup(repo_find_unique_abbrev(the_repository, oid2, DEFAULT_ABBREV));
 		htmlf("<br/>index %s..%s", abbrev1, abbrev2);
 		free(abbrev1);
 		free(abbrev2);
@@ -242,35 +274,30 @@ static void header(unsigned char *sha1, char *path1, int mode1,
 			if (mode2 != mode1)
 				htmlf("..%.6o", mode2);
 		}
-		html("<br/>--- a/");
+		if (is_null_oid(oid1)) {
+			path1 = "dev/null";
+			html("<br/>--- /");
+		} else
+			html("<br/>--- a/");
 		if (mode1 != 0)
 			cgit_tree_link(path1, NULL, NULL, ctx.qry.head,
-				       sha1_to_hex(old_rev_sha1), path1);
+				       oid_to_hex(old_rev_oid), path1);
 		else
 			html_txt(path1);
-		html("<br/>+++ b/");
+		if (is_null_oid(oid2)) {
+			path2 = "dev/null";
+			html("<br/>+++ /");
+		} else
+			html("<br/>+++ b/");
 		if (mode2 != 0)
 			cgit_tree_link(path2, NULL, NULL, ctx.qry.head,
-				       sha1_to_hex(new_rev_sha1), path2);
+				       oid_to_hex(new_rev_oid), path2);
 		else
 			html_txt(path2);
 	}
 	html("</div>");
 }
 
-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, ctx.qry.path, 1);
-		else
-			cgit_diff_link("Side-by-side diff", NULL, NULL,
-				       ctx.qry.head, ctx.qry.sha1,
-				       ctx.qry.sha2, ctx.qry.path, 1);
-	}
-}
-
 static void filepair_cb(struct diff_filepair *pair)
 {
 	unsigned long old_size = 0;
@@ -278,25 +305,30 @@ static void filepair_cb(struct diff_filepair *pair)
 	int binary = 0;
 	linediff_fn print_line_fn = print_line;
 
+	if (!show_filepair(pair))
+		return;
+
+	current_filepair = pair;
 	if (use_ssdiff) {
 		cgit_ssdiff_header_begin();
 		print_line_fn = cgit_ssdiff_line_cb;
 	}
-	header(pair->one->sha1, pair->one->path, pair->one->mode,
-	       pair->two->sha1, pair->two->path, pair->two->mode);
+	header(&pair->one->oid, pair->one->path, pair->one->mode,
+	       &pair->two->oid, pair->two->path, pair->two->mode);
 	if (use_ssdiff)
 		cgit_ssdiff_header_end();
 	if (S_ISGITLINK(pair->one->mode) || S_ISGITLINK(pair->two->mode)) {
 		if (S_ISGITLINK(pair->one->mode))
-			print_line_fn(fmt("-Subproject %s", sha1_to_hex(pair->one->sha1)), 52);
+			print_line_fn(fmt("-Subproject %s", oid_to_hex(&pair->one->oid)), 52);
 		if (S_ISGITLINK(pair->two->mode))
-			print_line_fn(fmt("+Subproject %s", sha1_to_hex(pair->two->sha1)), 52);
+			print_line_fn(fmt("+Subproject %s", oid_to_hex(&pair->two->oid)), 52);
 		if (use_ssdiff)
 			cgit_ssdiff_footer();
 		return;
 	}
-	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
-			    &new_size, &binary, ctx.qry.context, print_line_fn))
+	if (cgit_diff_files(&pair->one->oid, &pair->two->oid, &old_size,
+			    &new_size, &binary, ctx.qry.context,
+			    ctx.qry.ignorews, print_line_fn))
 		cgit_print_error("Error running diff");
 	if (binary) {
 		if (use_ssdiff)
@@ -308,47 +340,223 @@ static void filepair_cb(struct diff_filepair *pair)
 		cgit_ssdiff_footer();
 }
 
-void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefix)
+static int print_ref_option(const struct reference *ref, void *cb_data)
+{
+	const char **sel = (const char **)cb_data;
+
+	html_option(ref->name, ref->name, sel[0]);
+	return 0;
+}
+
+static void cgit_print_ref_select(const char *name, const char *selected)
+{
+	/*
+	 * Offer every branch and tag so that any two refs can be compared.
+	 */
+	html("<select name='");
+	html_attr(name);
+	html("' onchange='this.form.submit();'>");
+	refs_for_each_branch_ref(get_main_ref_store(the_repository),
+				 print_ref_option, (void *)&selected);
+	if (ctx.repo->enable_remote_branches)
+		refs_for_each_remote_ref(get_main_ref_store(the_repository),
+					  print_ref_option, (void *)&selected);
+	refs_for_each_tag_ref(get_main_ref_store(the_repository),
+			      print_ref_option, (void *)&selected);
+	html("</select>");
+}
+
+void cgit_print_diff_ctrls(void)
+{
+	int i, curr;
+
+	html("<form class='diff-ctrls' method='get'>");
+	/*
+	 * Emit the same hidden fields as cgit_add_hidden_formfields(), except
+	 * id/id2, which are carried by the ref-picker selects below.  One
+	 * form wraps both panels so any submission carries all controls.
+	 */
+	if (!ctx.cfg.virtual_root) {
+		struct strbuf url = STRBUF_INIT;
+		strbuf_addf(&url, "%s/%s", ctx.qry.repo, ctx.qry.page);
+		if (ctx.qry.vpath)
+			strbuf_addf(&url, "/%s", ctx.qry.vpath);
+		html_hidden("url", url.buf);
+		strbuf_release(&url);
+	}
+	if (ctx.qry.head && ctx.repo->defbranch &&
+	    strcmp(ctx.qry.head, ctx.repo->defbranch))
+		html_hidden("h", ctx.qry.head);
+	if (ctx.qry.showmsg)
+		html_hidden("showmsg", "1");
+
+	html("<div class='cgit-panel'>");
+	html("<b>diff refs</b>");
+	html("<table>");
+	html("<tr><td colspan='2'/></tr>");
+
+	/* ref pickers: compare any two refs (branches/tags) */
+	{
+		const char *new_ref = ctx.qry.oid ? ctx.qry.oid : ctx.qry.head;
+		const char *old_ref = ctx.qry.oid2;
+
+		html("<tr>");
+		html("<td class='label'>from:</td>");
+		html("<td class='ctrl'>");
+		cgit_print_ref_select("id2", old_ref);
+		html("</td></tr><tr>");
+		html("<td class='label'>to:</td>");
+		html("<td class='ctrl'>");
+		cgit_print_ref_select("id", new_ref);
+		html("</td></tr>");
+	}
+	html("</table>");
+	html("</div>");
+
+	html("<div class='cgit-panel'>");
+	html("<b>diff options</b>");
+	html("<table>");
+	html("<tr><td colspan='2'/></tr>");
+
+	html("<tr>");
+	html("<td class='label'>context:</td>");
+	html("<td class='ctrl'>");
+	html("<select name='context' onchange='this.form.submit();'>");
+	curr = ctx.qry.context;
+	if (!curr)
+		curr = 3;
+	for (i = 1; i <= 10; i++)
+		html_intoption(i, fmt("%d", i), curr);
+	for (i = 15; i <= 40; i += 5)
+		html_intoption(i, fmt("%d", i), curr);
+	html("</select>");
+	html("</td>");
+	html("</tr><tr>");
+	html("<td class='label'>space:</td>");
+	html("<td class='ctrl'>");
+	html("<select name='ignorews' onchange='this.form.submit();'>");
+	html_intoption(0, "include", ctx.qry.ignorews);
+	html_intoption(1, "ignore", ctx.qry.ignorews);
+	html("</select>");
+	html("</td>");
+	html("</tr><tr>");
+	html("<td class='label'>mode:</td>");
+	html("<td class='ctrl'>");
+	html("<select name='dt' onchange='this.form.submit();'>");
+	curr = ctx.qry.has_difftype ? ctx.qry.difftype : ctx.cfg.difftype;
+	html_intoption(0, "unified", curr);
+	html_intoption(1, "ssdiff", curr);
+	html_intoption(2, "stat only", curr);
+	html("</select></td></tr>");
+	html("<tr><td/><td class='ctrl'>");
+	html("<noscript><input type='submit' value='reload'/></noscript>");
+	html("</td></tr></table>");
+	html("</div>");
+	html("</form>");
+}
+
+void cgit_print_diff(const char *new_rev, const char *old_rev,
+		     const char *prefix, int show_ctrls, int raw)
 {
-	enum object_type type;
-	unsigned long size;
 	struct commit *commit, *commit2;
+	const struct object_id *old_tree_oid, *new_tree_oid;
+	diff_type difftype;
+
+	/*
+	 * If "follow" is set then the diff machinery needs to examine the
+	 * entire commit to detect renames so we must limit the paths in our
+	 * own callbacks and not pass the prefix to the diff machinery.
+	 */
+	if (ctx.qry.follow && ctx.repo->enable_follow_links) {
+		current_prefix = prefix;
+		prefix = "";
+	} else {
+		current_prefix = NULL;
+	}
 
 	if (!new_rev)
 		new_rev = ctx.qry.head;
-	get_sha1(new_rev, new_rev_sha1);
-	type = sha1_object_info(new_rev_sha1, &size);
-	if (type == OBJ_BAD) {
-		cgit_print_error(fmt("Bad object name: %s", new_rev));
+	if (repo_get_oid(the_repository, new_rev, new_rev_oid)) {
+		cgit_print_error_page(404, "Not found",
+			"Bad object name: %s", new_rev);
+		return;
+	}
+	commit = lookup_commit_reference(the_repository, new_rev_oid);
+	if (!commit || repo_parse_commit(the_repository, commit)) {
+		cgit_print_error_page(404, "Not found",
+			"Bad commit: %s", oid_to_hex(new_rev_oid));
 		return;
 	}
-	commit = lookup_commit_reference(new_rev_sha1);
-	if (!commit || parse_commit(commit))
-		cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(new_rev_sha1)));
+	new_tree_oid = get_commit_tree_oid(commit);
 
-	if (old_rev)
-		get_sha1(old_rev, old_rev_sha1);
-	else if (commit->parents && commit->parents->item)
-		hashcpy(old_rev_sha1, commit->parents->item->object.sha1);
-	else
-		hashclr(old_rev_sha1);
+	if (old_rev) {
+		if (repo_get_oid(the_repository, old_rev, old_rev_oid)) {
+			cgit_print_error_page(404, "Not found",
+				"Bad object name: %s", old_rev);
+			return;
+		}
+	} else if (commit->parents && commit->parents->item) {
+		oidcpy(old_rev_oid, &commit->parents->item->object.oid);
+	} else {
+		oidclr(old_rev_oid, the_repository->hash_algo);
+	}
 
-	if (!is_null_sha1(old_rev_sha1)) {
-		type = sha1_object_info(old_rev_sha1, &size);
-		if (type == OBJ_BAD) {
-			cgit_print_error(fmt("Bad object name: %s", sha1_to_hex(old_rev_sha1)));
+	if (!is_null_oid(old_rev_oid)) {
+		commit2 = lookup_commit_reference(the_repository, old_rev_oid);
+		if (!commit2 || repo_parse_commit(the_repository, commit2)) {
+			cgit_print_error_page(404, "Not found",
+				"Bad commit: %s", oid_to_hex(old_rev_oid));
 			return;
 		}
-		commit2 = lookup_commit_reference(old_rev_sha1);
-		if (!commit2 || parse_commit(commit2))
-			cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(old_rev_sha1)));
+		old_tree_oid = get_commit_tree_oid(commit2);
+	} else {
+		old_tree_oid = NULL;
+	}
+
+	if (raw) {
+		struct diff_options diffopt;
+
+		repo_diff_setup(the_repository, &diffopt);
+		diffopt.output_format = DIFF_FORMAT_PATCH;
+		diffopt.flags.recursive = 1;
+		diff_setup_done(&diffopt);
+
+		ctx.page.mimetype = "text/plain";
+		cgit_print_http_headers();
+		if (old_tree_oid) {
+			diff_tree_oid(old_tree_oid, new_tree_oid, "",
+				       &diffopt);
+		} else {
+			diff_root_tree_oid(new_tree_oid, "", &diffopt);
+		}
+		diffcore_std(&diffopt);
+		diff_flush(&diffopt);
+
+		return;
 	}
 
-	if ((ctx.qry.ssdiff && !ctx.cfg.ssdiff) || (!ctx.qry.ssdiff && ctx.cfg.ssdiff))
-		use_ssdiff = 1;
+	difftype = ctx.qry.has_difftype ? ctx.qry.difftype : ctx.cfg.difftype;
+	use_ssdiff = difftype == DIFF_SSDIFF;
+
+	if (show_ctrls) {
+		cgit_print_layout_start();
+		cgit_print_diff_ctrls();
+	}
 
-	print_ssdiff_link();
-	cgit_print_diffstat(old_rev_sha1, new_rev_sha1, prefix);
+	/*
+	 * Clicking on a link to a file in the diff stat should show a diff
+	 * of the file, showing the diff stat limited to a single file is
+	 * pretty useless.  All links from this point on will be to
+	 * individual files, so we simply reset the difftype in the query
+	 * here to avoid propagating DIFF_STATONLY to the individual files.
+	 */
+	if (difftype == DIFF_STATONLY)
+		ctx.qry.difftype = ctx.cfg.difftype;
+
+	cgit_print_diffstat(old_rev_oid, new_rev_oid, prefix);
+
+	if (difftype == DIFF_STATONLY)
+		return;
 
 	if (use_ssdiff) {
 		html("<table summary='ssdiff' class='ssdiff'>");
@@ -356,8 +564,12 @@ void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefi
 		html("<table summary='diff' class='diff'>");
 		html("<tr><td>");
 	}
-	cgit_diff_tree(old_rev_sha1, new_rev_sha1, filepair_cb, prefix);
+	cgit_diff_tree(old_rev_oid, new_rev_oid, filepair_cb, prefix,
+		       ctx.qry.ignorews);
 	if (!use_ssdiff)
 		html("</td></tr>");
 	html("</table>");
+
+	if (show_ctrls)
+		cgit_print_layout_end();
 }