ui-log: try to disambiguate ref names

The 'h' querystring parameter in cgit is normally used to specify
a branch (i.e. a ref below refs/heads/), but if a repository contains
a tag with the same name as a branch the output from ui-log would use
the tag as start-revision.

This patch tries to fix the issue by checking if the specified ref is
valid as a branch name; if so, the full refname is used in the call
to setup_revisions().

Noticed-by: Takamori Yamaguchi <akschar@gmail.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/ui-log.c b/ui-log.c
index 8dd8b89..d212984 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -19,108 +19,121 @@ void count_lines(char *line, int size)
 
         if (line[0] == '+')
                 add_lines++;
 
         else if (line[0] == '-')
                 rem_lines++;
 }
 
 void inspect_files(struct diff_filepair *pair)
 {
         files++;
         if (ctx.repo->enable_log_linecount)
                 cgit_diff_files(pair->one->sha1, pair->two->sha1, count_lines);
 }
 
 void print_commit(struct commit *commit)
 {
         struct commitinfo *info;
         char *tmp;
 
         info = cgit_parse_commit(commit);
         html("<tr><td>");
         tmp = fmt("id=%s", sha1_to_hex(commit->object.sha1));
         tmp = cgit_pageurl(ctx.repo->url, "commit", tmp);
         html_link_open(tmp, NULL, NULL);
         cgit_print_age(commit->date, TM_WEEK * 2, FMT_SHORTDATE);
         html_link_close();
         html("</td><td>");
         cgit_commit_link(info->subject, NULL, NULL, ctx.qry.head,
                          sha1_to_hex(commit->object.sha1));
         html("</td><td>");
         html_txt(info->author);
         if (ctx.repo->enable_log_filecount) {
                 files = 0;
                 add_lines = 0;
                 rem_lines = 0;
                 cgit_diff_commit(commit, inspect_files);
                 html("</td><td>");
                 htmlf("%d", files);
                 if (ctx.repo->enable_log_linecount) {
                         html("</td><td>");
                         htmlf("-%d/+%d", rem_lines, add_lines);
                 }
         }
         html("</td></tr>\n");
         cgit_free_commitinfo(info);
 }
 
+static const char *disambiguate_ref(const char *ref)
+{
+        unsigned char sha1[20];
+        const char *longref;
+
+        longref = fmt("refs/heads/%s", ref);
+        if (get_sha1(longref, sha1) == 0)
+                return longref;
+
+        return ref;
+}
 
 void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern,
                     char *path, int pager)
 {
         struct rev_info rev;
         struct commit *commit;
-        const char *argv[] = {NULL, tip, NULL, NULL, NULL};
+        const char *argv[] = {NULL, NULL, NULL, NULL, NULL};
         int argc = 2;
         int i, columns = 3;
 
         if (!tip)
-                argv[1] = ctx.qry.head;
+                tip = ctx.qry.head;
+
+        argv[1] = disambiguate_ref(tip);
 
         if (grep && pattern && (!strcmp(grep, "grep") ||
                                 !strcmp(grep, "author") ||
                                 !strcmp(grep, "committer")))
                 argv[argc++] = fmt("--%s=%s", grep, pattern);
 
         if (path) {
                 argv[argc++] = "--";
                 argv[argc++] = path;
         }
         init_revisions(&rev, NULL);
         rev.abbrev = DEFAULT_ABBREV;
         rev.commit_format = CMIT_FMT_DEFAULT;
         rev.verbose_header = 1;
         rev.show_root_diff = 0;
         setup_revisions(argc, argv, &rev, NULL);
         rev.grep_filter.regflags |= REG_ICASE;
         compile_grep_patterns(&rev.grep_filter);
         prepare_revision_walk(&rev);
 
         if (pager)
                 html("<table class='list nowrap'>");
 
         html("<tr class='nohover'><th class='left'>Age</th>"
              "<th class='left'>Commit message</th>"
              "<th class='left'>Author</th>");
         if (ctx.repo->enable_log_filecount) {
                 html("<th class='left'>Files</th>");
                 columns++;
                 if (ctx.repo->enable_log_linecount) {
                         html("<th class='left'>Lines</th>");
                         columns++;
                 }
         }
         html("</tr>\n");
 
         if (ofs<0)
                 ofs = 0;
 
         for (i = 0; i < ofs && (commit = get_revision(&rev)) != NULL; i++) {
                 free(commit->buffer);
                 commit->buffer = NULL;
                 free_commit_list(commit->parents);
                 commit->parents = NULL;
         }
 
         for (i = 0; i < cnt && (commit = get_revision(&rev)) != NULL; i++) {
                 print_commit(commit);