Add support for commitdiff via h parameter

The commitdiff will be generated against the first parent, and the
diff page also gets the benefit of repo.defbranch.

Cleaned up some bad whitespace in cgit.h while at it.

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

3 files changed, 21 insertions, 7 deletions

diff --git a/cgit.c b/cgit.c
index 9b4815d..3e7e595 100644
--- a/cgit.c
+++ b/cgit.c
@@ -59,129 +59,130 @@ static int cgit_prepare_cache(struct cacheitem *item)
 	}
 	return 1;
 }
 
 static void cgit_print_repo_page(struct cacheitem *item)
 {
 	char *title;
 	int show_search;
 
 	if (!cgit_query_head)
 		cgit_query_head = cgit_repo->defbranch;
 
 	if (chdir(cgit_repo->path)) {
 		title = fmt("%s - %s", cgit_root_title, "Bad request");
 		cgit_print_docstart(title, item);
 		cgit_print_pageheader(title, 0);
 		cgit_print_error(fmt("Unable to scan repository: %s",
 				     strerror(errno)));
 		cgit_print_docend();
 		return;
 	}
 
 	title = fmt("%s - %s", cgit_repo->name, cgit_repo->desc);
 	show_search = 0;
 	setenv("GIT_DIR", cgit_repo->path, 1);
 
 	if (cgit_query_page) {
 	    if (cgit_repo->snapshots && !strcmp(cgit_query_page, "snapshot")) {
 		cgit_print_snapshot(item, cgit_query_sha1, "zip",
 				    cgit_repo->url, cgit_query_name);
 		return;
 	    }
 	    if (!strcmp(cgit_query_page, "blob")) {
 		    cgit_print_blob(item, cgit_query_sha1, cgit_query_path);
 		    return;
 	    }
 	}
 
 	if (cgit_query_page && !strcmp(cgit_query_page, "log"))
 		show_search = 1;
 
 	cgit_print_docstart(title, item);
 
 
 	if (!cgit_query_page) {
 		cgit_print_pageheader("summary", show_search);
 		cgit_print_summary();
 		cgit_print_docend();
 		return;
 	}
 
 	cgit_print_pageheader(cgit_query_page, show_search);
 
 	if (!strcmp(cgit_query_page, "log")) {
 		cgit_print_log(cgit_query_head, cgit_query_ofs,
 			       cgit_max_commit_count, cgit_query_search,
 			       cgit_query_path);
 	} else if (!strcmp(cgit_query_page, "tree")) {
 		cgit_print_tree(cgit_query_head, cgit_query_sha1, cgit_query_path);
 	} else if (!strcmp(cgit_query_page, "commit")) {
 		cgit_print_commit(cgit_query_head);
 	} else if (!strcmp(cgit_query_page, "view")) {
 		cgit_print_view(cgit_query_sha1, cgit_query_path);
 	} else if (!strcmp(cgit_query_page, "diff")) {
-		cgit_print_diff(cgit_query_sha1, cgit_query_sha2, cgit_query_path);
+		cgit_print_diff(cgit_query_head, cgit_query_sha1, cgit_query_sha2,
+				cgit_query_path);
 	} else {
 		cgit_print_error("Invalid request");
 	}
 	cgit_print_docend();
 }
 
 static void cgit_fill_cache(struct cacheitem *item, int use_cache)
 {
 	static char buf[PATH_MAX];
 	int stdout2;
 
 	getcwd(buf, sizeof(buf));
 	item->st.st_mtime = time(NULL);
 
 	if (use_cache) {
 		stdout2 = chk_positive(dup(STDOUT_FILENO),
 				       "Preserving STDOUT");
 		chk_zero(close(STDOUT_FILENO), "Closing STDOUT");
 		chk_positive(dup2(item->fd, STDOUT_FILENO), "Dup2(cachefile)");
 	}
 
 	if (cgit_query_repo)
 		cgit_print_repo_page(item);
 	else
 		cgit_print_repolist(item);
 
 	if (use_cache) {
 		chk_zero(close(STDOUT_FILENO), "Close redirected STDOUT");
 		chk_positive(dup2(stdout2, STDOUT_FILENO),
 			     "Restoring original STDOUT");
 		chk_zero(close(stdout2), "Closing temporary STDOUT");
 	}
 
 	chdir(buf);
 }
 
 static void cgit_check_cache(struct cacheitem *item)
 {
 	int i = 0;
 
  top:
 	if (++i > cgit_max_lock_attempts) {
 		die("cgit_refresh_cache: unable to lock %s: %s",
 		    item->name, strerror(errno));
 	}
 	if (!cache_exist(item)) {
 		if (!cache_lock(item)) {
 			sleep(1);
 			goto top;
 		}
 		if (!cache_exist(item)) {
 			cgit_fill_cache(item, 1);
 			cache_unlock(item);
 		} else {
 			cache_cancel_lock(item);
 		}
 	} else if (cache_expired(item) && cache_lock(item)) {
 		if (cache_expired(item)) {
 			cgit_fill_cache(item, 1);
 			cache_unlock(item);
 		} else {
 			cache_cancel_lock(item);
 		}
 	}
diff --git a/cgit.h b/cgit.h
index ac710a6..764225d 100644
--- a/cgit.h
+++ b/cgit.h
@@ -96,89 +96,90 @@ extern char *cgit_repo_desc;
 extern char *cgit_repo_owner;
 
 extern int cgit_query_has_symref;
 extern int cgit_query_has_sha1;
 
 extern char *cgit_querystring;
 extern char *cgit_query_repo;
 extern char *cgit_query_page;
 extern char *cgit_query_search;
 extern char *cgit_query_head;
 extern char *cgit_query_sha1;
 extern char *cgit_query_sha2;
 extern char *cgit_query_path;
 extern char *cgit_query_name;
 extern int   cgit_query_ofs;
 
 extern int htmlfd;
 
 extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
 
 extern int hextoint(char c);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern int cgit_diff_files(const unsigned char *old_sha1,
 			   const unsigned char *new_sha1,
 			   linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
 			   const unsigned char *new_sha1,
 			   filepair_fn fn);
 
 extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
 
 extern char *fmt(const char *format,...);
 
 extern void html(const char *txt);
 extern void htmlf(const char *format,...);
 extern void html_txt(char *txt);
 extern void html_ntxt(int len, char *txt);
 extern void html_attr(char *txt);
 extern void html_hidden(char *name, char *value);
 extern void html_link_open(char *url, char *title, char *class);
 extern void html_link_close(void);
 extern void html_filemode(unsigned short mode);
 
 extern int cgit_read_config(const char *filename, configfn fn);
 extern int cgit_parse_query(char *txt, configfn fn);
 extern struct commitinfo *cgit_parse_commit(struct commit *commit);
 extern struct taginfo *cgit_parse_tag(struct tag *tag);
 
 extern char *cache_safe_filename(const char *unsafe);
 extern int cache_lock(struct cacheitem *item);
 extern int cache_unlock(struct cacheitem *item);
 extern int cache_cancel_lock(struct cacheitem *item);
 extern int cache_exist(struct cacheitem *item);
 extern int cache_expired(struct cacheitem *item);
 
 extern char *cgit_repourl(const char *reponame);
-extern char *cgit_pageurl(const char *reponame, const char *pagename, 
+extern char *cgit_pageurl(const char *reponame, const char *pagename,
 			  const char *query);
 
 extern void cgit_print_error(char *msg);
 extern void cgit_print_date(unsigned long secs);
 extern void cgit_print_docstart(char *title, struct cacheitem *item);
 extern void cgit_print_docend();
 extern void cgit_print_pageheader(char *title, int show_search);
-extern void cgit_print_snapshot_start(const char *mimetype, 
-				      const char *filename, 
+extern void cgit_print_snapshot_start(const char *mimetype,
+				      const char *filename,
 				      struct cacheitem *item);
 
 extern void cgit_print_repolist(struct cacheitem *item);
 extern void cgit_print_summary();
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *path);
 extern void cgit_print_view(const char *hex, char *path);
 extern void cgit_print_blob(struct cacheitem *item, const char *hex, char *path);
 extern void cgit_print_tree(const char *rev, const char *hex, char *path);
 extern void cgit_print_commit(const char *hex);
-extern void cgit_print_diff(const char *old_hex, const char *new_hex, char *path);
-extern void cgit_print_snapshot(struct cacheitem *item, const char *hex, 
+extern void cgit_print_diff(const char *head, const char *old_hex, const char *new_hex,
+			    char *path);
+extern void cgit_print_snapshot(struct cacheitem *item, const char *hex,
 				const char *format, const char *prefix,
 				const char *filename);
 
 #endif /* CGIT_H */
diff --git a/ui-diff.c b/ui-diff.c
index 999b6f3..afe1c90 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -5,101 +5,113 @@
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
 
 /*
  * print a single line returned from xdiff
  */
 static void print_line(char *line, int len)
 {
 	char *class = "ctx";
 	char c = line[len-1];
 
 	if (line[0] == '+')
 		class = "add";
 	else if (line[0] == '-')
 		class = "del";
 	else if (line[0] == '@')
 		class = "hunk";
 
 	htmlf("<div class='%s'>", class);
 	line[len-1] = '\0';
 	html_txt(line);
 	html("</div>");
 	line[len-1] = c;
 }
 
 static void header(unsigned char *sha1, char *path1,
 		   unsigned char *sha2, char *path2)
 {
 	char *abbrev1, *abbrev2;
 	if (is_null_sha1(sha1))
 		path1 = "dev/null";
 	if (is_null_sha1(sha2))
 		path2 = "dev/null";
 	html("<tr><td>");
 	html("<div class='head'>");
 	html("diff --git a/");
 	html_txt(path1);
 	html(" b/");
 	html_txt(path2);
 	abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
 	abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
 	htmlf("\nindex %s..%s", abbrev1, abbrev2);
 	free(abbrev1);
 	free(abbrev2);
 	html("\n--- a/");
 	html_txt(path1);
 	html("\n+++ b/");
 	html_txt(path2);
 	html("</div>");
 }
 
 static void filepair_cb(struct diff_filepair *pair)
 {
 	header(pair->one->sha1, pair->one->path,
 	       pair->two->sha1, pair->two->path);
 	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, print_line))
 		cgit_print_error("Error running diff");
 	html("</tr></td>");
 }
 
-void cgit_print_diff(const char *old_hex, const char *new_hex, char *path)
+void cgit_print_diff(const char *head, const char *old_hex, const char *new_hex, char *path)
 {
 	unsigned char sha1[20], sha2[20];
 	enum object_type type;
 	unsigned long size;
+	struct commit *commit;
+
+	if (head && !old_hex && !new_hex) {
+		get_sha1(head, sha1);
+		commit = lookup_commit_reference(sha1);
+		if (commit && !parse_commit(commit)) {
+			html("<table class='diff'>");
+			cgit_diff_commit(commit, filepair_cb);
+			html("</td></tr></table>");
+		}
+		return;
+	}
 
 	get_sha1(old_hex, sha1);
 	get_sha1(new_hex, sha2);
 
 	type = sha1_object_info(sha1, &size);
 	if (type == OBJ_BAD) {
 		type = sha1_object_info(sha2, &size);
 		if (type == OBJ_BAD) {
 			cgit_print_error(fmt("Bad object names: %s, %s", old_hex, new_hex));
 			return;
 		}
 	}
 
 	html("<table class='diff'>");
 	switch(type) {
 	case OBJ_BLOB:
 		html("<tr><td>");
 		header(sha1, path, sha2, path);
 		if (cgit_diff_files(sha1, sha2, print_line))
 			cgit_print_error("Error running diff");
 		html("</tr></td>");
 		break;
 	case OBJ_TREE:
 		cgit_diff_tree(sha1, sha2, filepair_cb);
 		break;
 	default:
 		cgit_print_error(fmt("Unhandled object type: %s",
 				     typename(type)));
 		break;
 	}
 	html("</td></tr></table>");
 }