+/* Try to guess the requested revision by combining repo name and tag name
+ * and comparing this to the requested snapshot name. E.g. the requested
+ * snapshot is "cgit-0.7.2.tar.gz" while repo name is "cgit" and tag name
+ * is "v0.7.2". First, the reponame is stripped off, leaving "-0.7.2.tar.gz".
+ * Next, any '-' and '_' characters are stripped, leaving "0.7.2.tar.gz".
+ * Finally, the requested format suffix is removed and we end up with "0.7.2".
+ * Then we test each tag against this dwimmed filename, and for each tag
+ * we even try to remove any leading characters which are non-digits. I.e.
+ * we first compare with "v0.7.2", then with "0.7.2" and we've got a match.
+ */
+static const char *get_ref_from_filename(const char *url, const char *filename,
+ const struct cgit_snapshot_format *fmt)
+{
+ const char *reponame = cgit_repobasename(url);
+ fprintf(stderr, "reponame=%s, filename=%s\n", reponame, filename);
+ if (prefixcmp(filename, reponame))
+ return NULL;
+ filename += strlen(reponame);
+ while (filename && (*filename == '-' || *filename == '_'))
+ filename++;
+ dwim_filename = xstrdup(filename);
+ dwim_filename[strlen(filename) - strlen(fmt->suffix)] = '\0';
+ for_each_tag_ref(ref_cb, NULL);
+ return dwim_refname;
+}
+
+void cgit_print_snapshot(const char *head, const char *hex, const char *prefix,
+ const char *filename, int snapshots, int dwim)
+{
+ const struct cgit_snapshot_format* f;
+
+ f = get_format(filename);
+ if (!f) {
+ ctx.page.mimetype = "text/html";
+ cgit_print_http_headers(&ctx);
+ cgit_print_docstart(&ctx);
+ cgit_print_pageheader(&ctx);
+ cgit_print_error(fmt("Unsupported snapshot format: %s", filename));
+ cgit_print_docend();
+ return;
+ }
+
+ if (!hex && dwim)
+ hex = get_ref_from_filename(ctx.repo->url, filename, f);
+
+ if (!hex)
+ hex = head;
+
+ make_snapshot(f, hex, prefix, filename);
+}