cgit.c: improve error message when git repo cannot be accessed

The current 'Not a git repository' error message is not very helpful,
since it doesn't state the cause of the problem.

This patch uses errno to provide a hint of the underlying problem. It
would have been even better to give the exact cause (e.g. for ENOENT it
would be nice to know which file/directory is missing), but that would
require reimplementing setup_git_directory_gently() which seems a bit
overkill.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/cgit.c b/cgit.c
index e498030..5259f56 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1,797 +1,801 @@
 /* cgit.c: cgi for the git scm
  *
  * Copyright (C) 2006 Lars Hjemli
  * Copyright (C) 2010 Jason A. Donenfeld <Jason@zx2c4.com>
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "cache.h"
 #include "cmd.h"
 #include "configfile.h"
 #include "html.h"
 #include "ui-shared.h"
 #include "ui-stats.h"
 #include "scan-tree.h"
 
 const char *cgit_version = CGIT_VERSION;
 
 void add_mimetype(const char *name, const char *value)
 {
         struct string_list_item *item;
 
         item = string_list_insert(&ctx.cfg.mimetypes, xstrdup(name));
         item->util = xstrdup(value);
 }
 
 struct cgit_filter *new_filter(const char *cmd, int extra_args)
 {
         struct cgit_filter *f;
         int args_size = 0;
 
         if (!cmd || !cmd[0])
                 return NULL;
 
         f = xmalloc(sizeof(struct cgit_filter));
         f->cmd = xstrdup(cmd);
         args_size = (2 + extra_args) * sizeof(char *);
         f->argv = xmalloc(args_size);
         memset(f->argv, 0, args_size);
         f->argv[0] = f->cmd;
         return f;
 }
 
 static void process_cached_repolist(const char *path);
 
 void repo_config(struct cgit_repo *repo, const char *name, const char *value)
 {
         if (!strcmp(name, "name"))
                 repo->name = xstrdup(value);
         else if (!strcmp(name, "clone-url"))
                 repo->clone_url = xstrdup(value);
         else if (!strcmp(name, "desc"))
                 repo->desc = xstrdup(value);
         else if (!strcmp(name, "owner"))
                 repo->owner = xstrdup(value);
         else if (!strcmp(name, "defbranch"))
                 repo->defbranch = xstrdup(value);
         else if (!strcmp(name, "snapshots"))
                 repo->snapshots = ctx.cfg.snapshots & cgit_parse_snapshots_mask(value);
         else if (!strcmp(name, "enable-commit-graph"))
                 repo->enable_commit_graph = ctx.cfg.enable_commit_graph * atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 repo->enable_log_filecount = ctx.cfg.enable_log_filecount * atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 repo->enable_log_linecount = ctx.cfg.enable_log_linecount * atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 repo->enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 repo->enable_subject_links = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 repo->max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "module-link"))
                 repo->module_link= xstrdup(value);
         else if (!strcmp(name, "section"))
                 repo->section = xstrdup(value);
         else if (!strcmp(name, "readme") && value != NULL)
                 repo->readme = xstrdup(value);
         else if (!strcmp(name, "logo") && value != NULL)
                 repo->logo = xstrdup(value);
         else if (!strcmp(name, "logo-link") && value != NULL)
                 repo->logo_link = xstrdup(value);
         else if (ctx.cfg.enable_filter_overrides) {
                 if (!strcmp(name, "about-filter"))
                         repo->about_filter = new_filter(value, 0);
                 else if (!strcmp(name, "commit-filter"))
                         repo->commit_filter = new_filter(value, 0);
                 else if (!strcmp(name, "source-filter"))
                         repo->source_filter = new_filter(value, 1);
         }
 }
 
 void config_cb(const char *name, const char *value)
 {
         if (!strcmp(name, "section") || !strcmp(name, "repo.group"))
                 ctx.cfg.section = xstrdup(value);
         else if (!strcmp(name, "repo.url"))
                 ctx.repo = cgit_add_repo(value);
         else if (ctx.repo && !strcmp(name, "repo.path"))
                 ctx.repo->path = trim_end(value, '/');
         else if (ctx.repo && !prefixcmp(name, "repo."))
                 repo_config(ctx.repo, name + 5, value);
         else if (!strcmp(name, "readme"))
                 ctx.cfg.readme = xstrdup(value);
         else if (!strcmp(name, "root-title"))
                 ctx.cfg.root_title = xstrdup(value);
         else if (!strcmp(name, "root-desc"))
                 ctx.cfg.root_desc = xstrdup(value);
         else if (!strcmp(name, "root-readme"))
                 ctx.cfg.root_readme = xstrdup(value);
         else if (!strcmp(name, "css"))
                 ctx.cfg.css = xstrdup(value);
         else if (!strcmp(name, "favicon"))
                 ctx.cfg.favicon = xstrdup(value);
         else if (!strcmp(name, "footer"))
                 ctx.cfg.footer = xstrdup(value);
         else if (!strcmp(name, "head-include"))
                 ctx.cfg.head_include = xstrdup(value);
         else if (!strcmp(name, "header"))
                 ctx.cfg.header = xstrdup(value);
         else if (!strcmp(name, "logo"))
                 ctx.cfg.logo = xstrdup(value);
         else if (!strcmp(name, "index-header"))
                 ctx.cfg.index_header = xstrdup(value);
         else if (!strcmp(name, "index-info"))
                 ctx.cfg.index_info = xstrdup(value);
         else if (!strcmp(name, "logo-link"))
                 ctx.cfg.logo_link = xstrdup(value);
         else if (!strcmp(name, "module-link"))
                 ctx.cfg.module_link = xstrdup(value);
         else if (!strcmp(name, "strict-export"))
                 ctx.cfg.strict_export = xstrdup(value);
         else if (!strcmp(name, "virtual-root")) {
                 ctx.cfg.virtual_root = trim_end(value, '/');
                 if (!ctx.cfg.virtual_root && (!strcmp(value, "/")))
                         ctx.cfg.virtual_root = "";
         } else if (!strcmp(name, "nocache"))
                 ctx.cfg.nocache = atoi(value);
         else if (!strcmp(name, "noplainemail"))
                 ctx.cfg.noplainemail = atoi(value);
         else if (!strcmp(name, "noheader"))
                 ctx.cfg.noheader = atoi(value);
         else if (!strcmp(name, "snapshots"))
                 ctx.cfg.snapshots = cgit_parse_snapshots_mask(value);
         else if (!strcmp(name, "enable-filter-overrides"))
                 ctx.cfg.enable_filter_overrides = atoi(value);
         else if (!strcmp(name, "enable-gitweb-owner"))
                 ctx.cfg.enable_gitweb_owner = atoi(value);
         else if (!strcmp(name, "enable-index-links"))
                 ctx.cfg.enable_index_links = atoi(value);
         else if (!strcmp(name, "enable-commit-graph"))
                 ctx.cfg.enable_commit_graph = atoi(value);
         else if (!strcmp(name, "enable-log-filecount"))
                 ctx.cfg.enable_log_filecount = atoi(value);
         else if (!strcmp(name, "enable-log-linecount"))
                 ctx.cfg.enable_log_linecount = atoi(value);
         else if (!strcmp(name, "enable-remote-branches"))
                 ctx.cfg.enable_remote_branches = atoi(value);
         else if (!strcmp(name, "enable-subject-links"))
                 ctx.cfg.enable_subject_links = atoi(value);
         else if (!strcmp(name, "enable-tree-linenumbers"))
                 ctx.cfg.enable_tree_linenumbers = atoi(value);
         else if (!strcmp(name, "max-stats"))
                 ctx.cfg.max_stats = cgit_find_stats_period(value, NULL);
         else if (!strcmp(name, "cache-size"))
                 ctx.cfg.cache_size = atoi(value);
         else if (!strcmp(name, "cache-root"))
                 ctx.cfg.cache_root = xstrdup(expand_macros(value));
         else if (!strcmp(name, "cache-root-ttl"))
                 ctx.cfg.cache_root_ttl = atoi(value);
         else if (!strcmp(name, "cache-repo-ttl"))
                 ctx.cfg.cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-scanrc-ttl"))
                 ctx.cfg.cache_scanrc_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 ctx.cfg.cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 ctx.cfg.cache_dynamic_ttl = atoi(value);
         else if (!strcmp(name, "about-filter"))
                 ctx.cfg.about_filter = new_filter(value, 0);
         else if (!strcmp(name, "commit-filter"))
                 ctx.cfg.commit_filter = new_filter(value, 0);
         else if (!strcmp(name, "embedded"))
                 ctx.cfg.embedded = atoi(value);
         else if (!strcmp(name, "max-atom-items"))
                 ctx.cfg.max_atom_items = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 ctx.cfg.max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 ctx.cfg.max_repodesc_len = atoi(value);
         else if (!strcmp(name, "max-blob-size"))
                 ctx.cfg.max_blob_size = atoi(value);
         else if (!strcmp(name, "max-repo-count"))
                 ctx.cfg.max_repo_count = atoi(value);
         else if (!strcmp(name, "max-commit-count"))
                 ctx.cfg.max_commit_count = atoi(value);
         else if (!strcmp(name, "project-list"))
                 ctx.cfg.project_list = xstrdup(expand_macros(value));
         else if (!strcmp(name, "scan-path"))
                 if (!ctx.cfg.nocache && ctx.cfg.cache_size)
                         process_cached_repolist(expand_macros(value));
                 else if (ctx.cfg.project_list)
                         scan_projects(expand_macros(value),
                                       ctx.cfg.project_list, repo_config);
                 else
                         scan_tree(expand_macros(value), repo_config);
         else if (!strcmp(name, "scan-hidden-path"))
                 ctx.cfg.scan_hidden_path = atoi(value);
         else if (!strcmp(name, "section-from-path"))
                 ctx.cfg.section_from_path = atoi(value);
         else if (!strcmp(name, "source-filter"))
                 ctx.cfg.source_filter = new_filter(value, 1);
         else if (!strcmp(name, "summary-log"))
                 ctx.cfg.summary_log = atoi(value);
         else if (!strcmp(name, "summary-branches"))
                 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"))
                 ctx.cfg.renamelimit = atoi(value);
         else if (!strcmp(name, "remove-suffix"))
                 ctx.cfg.remove_suffix = atoi(value);
         else if (!strcmp(name, "robots"))
                 ctx.cfg.robots = xstrdup(value);
         else if (!strcmp(name, "clone-prefix"))
                 ctx.cfg.clone_prefix = xstrdup(value);
         else if (!strcmp(name, "local-time"))
                 ctx.cfg.local_time = atoi(value);
         else if (!prefixcmp(name, "mimetype."))
                 add_mimetype(name + 9, value);
         else if (!strcmp(name, "include"))
                 parse_configfile(expand_macros(value), config_cb);
 }
 
 static void querystring_cb(const char *name, const char *value)
 {
         if (!value)
                 value = "";
 
         if (!strcmp(name,"r")) {
                 ctx.qry.repo = xstrdup(value);
                 ctx.repo = cgit_get_repoinfo(value);
         } else if (!strcmp(name, "p")) {
                 ctx.qry.page = xstrdup(value);
         } else if (!strcmp(name, "url")) {
                 if (*value == '/')
                         value++;
                 ctx.qry.url = xstrdup(value);
                 cgit_parse_url(value);
         } else if (!strcmp(name, "qt")) {
                 ctx.qry.grep = xstrdup(value);
         } else if (!strcmp(name, "q")) {
                 ctx.qry.search = xstrdup(value);
         } else if (!strcmp(name, "h")) {
                 ctx.qry.head = xstrdup(value);
                 ctx.qry.has_symref = 1;
         } else if (!strcmp(name, "id")) {
                 ctx.qry.sha1 = xstrdup(value);
                 ctx.qry.has_sha1 = 1;
         } else if (!strcmp(name, "id2")) {
                 ctx.qry.sha2 = xstrdup(value);
                 ctx.qry.has_sha1 = 1;
         } else if (!strcmp(name, "ofs")) {
                 ctx.qry.ofs = atoi(value);
         } else if (!strcmp(name, "path")) {
                 ctx.qry.path = trim_end(value, '/');
         } else if (!strcmp(name, "name")) {
                 ctx.qry.name = xstrdup(value);
         } else if (!strcmp(name, "mimetype")) {
                 ctx.qry.mimetype = xstrdup(value);
         } else if (!strcmp(name, "s")){
                 ctx.qry.sort = xstrdup(value);
         } else if (!strcmp(name, "showmsg")) {
                 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);
         } else if (!strcmp(name, "all")) {
                 ctx.qry.show_all = atoi(value);
         } else if (!strcmp(name, "context")) {
                 ctx.qry.context = atoi(value);
         } else if (!strcmp(name, "ignorews")) {
                 ctx.qry.ignorews = atoi(value);
         }
 }
 
 char *xstrdupn(const char *str)
 {
         return (str ? xstrdup(str) : NULL);
 }
 
 static void prepare_context(struct cgit_context *ctx)
 {
         memset(ctx, 0, sizeof(*ctx));
         ctx->cfg.agefile = "info/web/last-modified";
         ctx->cfg.nocache = 0;
         ctx->cfg.cache_size = 0;
         ctx->cfg.cache_dynamic_ttl = 5;
         ctx->cfg.cache_max_create_time = 5;
         ctx->cfg.cache_repo_ttl = 5;
         ctx->cfg.cache_root = CGIT_CACHE_ROOT;
         ctx->cfg.cache_root_ttl = 5;
         ctx->cfg.cache_scanrc_ttl = 15;
         ctx->cfg.cache_static_ttl = -1;
         ctx->cfg.css = "/cgit.css";
         ctx->cfg.logo = "/cgit.png";
         ctx->cfg.local_time = 0;
         ctx->cfg.enable_gitweb_owner = 1;
         ctx->cfg.enable_tree_linenumbers = 1;
         ctx->cfg.max_repo_count = 50;
         ctx->cfg.max_commit_count = 50;
         ctx->cfg.max_lock_attempts = 5;
         ctx->cfg.max_msg_len = 80;
         ctx->cfg.max_repodesc_len = 80;
         ctx->cfg.max_blob_size = 0;
         ctx->cfg.max_stats = 0;
         ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
         ctx->cfg.project_list = NULL;
         ctx->cfg.renamelimit = -1;
         ctx->cfg.remove_suffix = 0;
         ctx->cfg.robots = "index, nofollow";
         ctx->cfg.root_title = "Git repository browser";
         ctx->cfg.root_desc = "a fast webinterface for the git dscm";
         ctx->cfg.scan_hidden_path = 0;
         ctx->cfg.script_name = CGIT_SCRIPT_NAME;
         ctx->cfg.section = "";
         ctx->cfg.summary_branches = 10;
         ctx->cfg.summary_log = 10;
         ctx->cfg.summary_tags = 10;
         ctx->cfg.max_atom_items = 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"));
         ctx->env.no_http = xstrdupn(getenv("NO_HTTP"));
         ctx->env.path_info = xstrdupn(getenv("PATH_INFO"));
         ctx->env.query_string = xstrdupn(getenv("QUERY_STRING"));
         ctx->env.request_method = xstrdupn(getenv("REQUEST_METHOD"));
         ctx->env.script_name = xstrdupn(getenv("SCRIPT_NAME"));
         ctx->env.server_name = xstrdupn(getenv("SERVER_NAME"));
         ctx->env.server_port = xstrdupn(getenv("SERVER_PORT"));
         ctx->page.mimetype = "text/html";
         ctx->page.charset = PAGE_ENCODING;
         ctx->page.filename = NULL;
         ctx->page.size = 0;
         ctx->page.modified = time(NULL);
         ctx->page.expires = ctx->page.modified;
         ctx->page.etag = NULL;
         memset(&ctx->cfg.mimetypes, 0, sizeof(struct string_list));
         if (ctx->env.script_name)
                 ctx->cfg.script_name = ctx->env.script_name;
         if (ctx->env.query_string)
                 ctx->qry.raw = ctx->env.query_string;
         if (!ctx->env.cgit_config)
                 ctx->env.cgit_config = CGIT_CONFIG;
 }
 
 struct refmatch {
         char *req_ref;
         char *first_ref;
         int match;
 };
 
 int find_current_ref(const char *refname, const unsigned char *sha1,
                      int flags, void *cb_data)
 {
         struct refmatch *info;
 
         info = (struct refmatch *)cb_data;
         if (!strcmp(refname, info->req_ref))
                 info->match = 1;
         if (!info->first_ref)
                 info->first_ref = xstrdup(refname);
         return info->match;
 }
 
 char *find_default_branch(struct cgit_repo *repo)
 {
         struct refmatch info;
         char *ref;
 
         info.req_ref = repo->defbranch;
         info.first_ref = NULL;
         info.match = 0;
         for_each_branch_ref(find_current_ref, &info);
         if (info.match)
                 ref = info.req_ref;
         else
                 ref = info.first_ref;
         if (ref)
                 ref = xstrdup(ref);
         return ref;
 }
 
 static int prepare_repo_cmd(struct cgit_context *ctx)
 {
         char *tmp;
         unsigned char sha1[20];
         int nongit = 0;
+        int rc;
 
         setenv("GIT_DIR", ctx->repo->path, 1);
         setup_git_directory_gently(&nongit);
         if (nongit) {
+                rc = errno;
                 ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
                                       "config error");
-                tmp = fmt("Not a git repository: '%s'", ctx->repo->path);
+                tmp = fmt("Failed to open %s: %s",
+                          ctx->repo->name,
+                          rc ? strerror(rc) : "Not a valid git repository");
                 ctx->repo = NULL;
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(tmp);
                 cgit_print_docend();
                 return 1;
         }
         ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
 
         if (!ctx->qry.head) {
                 ctx->qry.nohead = 1;
                 ctx->qry.head = find_default_branch(ctx->repo);
                 ctx->repo->defbranch = ctx->qry.head;
         }
 
         if (!ctx->qry.head) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error("Repository seems to be empty");
                 cgit_print_docend();
                 return 1;
         }
 
         if (get_sha1(ctx->qry.head, sha1)) {
                 tmp = xstrdup(ctx->qry.head);
                 ctx->qry.head = ctx->repo->defbranch;
                 ctx->page.status = 404;
                 ctx->page.statusmsg = "not found";
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("Invalid branch: %s", tmp));
                 cgit_print_docend();
                 return 1;
         }
         return 0;
 }
 
 static void process_request(void *cbdata)
 {
         struct cgit_context *ctx = cbdata;
         struct cgit_cmd *cmd;
 
         cmd = cgit_get_cmd(ctx);
         if (!cmd) {
                 ctx->page.title = "cgit error";
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error("Invalid request");
                 cgit_print_docend();
                 return;
         }
 
         /* If cmd->want_vpath is set, assume ctx->qry.path contains a "virtual"
          * in-project path limit to be made available at ctx->qry.vpath.
          * Otherwise, no path limit is in effect (ctx->qry.vpath = NULL).
          */
         ctx->qry.vpath = cmd->want_vpath ? ctx->qry.path : NULL;
 
         if (cmd->want_repo && !ctx->repo) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
                 cgit_print_error(fmt("No repository selected"));
                 cgit_print_docend();
                 return;
         }
 
         if (ctx->repo && prepare_repo_cmd(ctx))
                 return;
 
         if (cmd->want_layout) {
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
                 cgit_print_pageheader(ctx);
         }
 
         cmd->fn(ctx);
 
         if (cmd->want_layout)
                 cgit_print_docend();
 }
 
 int cmp_repos(const void *a, const void *b)
 {
         const struct cgit_repo *ra = a, *rb = b;
         return strcmp(ra->url, rb->url);
 }
 
 char *build_snapshot_setting(int bitmap)
 {
         const struct cgit_snapshot_format *f;
         char *result = xstrdup("");
         char *tmp;
         int len;
 
         for (f = cgit_snapshot_formats; f->suffix; f++) {
                 if (f->bit & bitmap) {
                         tmp = result;
                         result = xstrdup(fmt("%s%s ", tmp, f->suffix));
                         free(tmp);
                 }
         }
         len = strlen(result);
         if (len)
                 result[len - 1] = '\0';
         return result;
 }
 
 char *get_first_line(char *txt)
 {
         char *t = xstrdup(txt);
         char *p = strchr(t, '\n');
         if (p)
                 *p = '\0';
         return t;
 }
 
 void print_repo(FILE *f, struct cgit_repo *repo)
 {
         fprintf(f, "repo.url=%s\n", repo->url);
         fprintf(f, "repo.name=%s\n", repo->name);
         fprintf(f, "repo.path=%s\n", repo->path);
         if (repo->owner)
                 fprintf(f, "repo.owner=%s\n", repo->owner);
         if (repo->desc) {
                 char *tmp = get_first_line(repo->desc);
                 fprintf(f, "repo.desc=%s\n", tmp);
                 free(tmp);
         }
         if (repo->readme)
                 fprintf(f, "repo.readme=%s\n", repo->readme);
         if (repo->defbranch)
                 fprintf(f, "repo.defbranch=%s\n", repo->defbranch);
         if (repo->module_link)
                 fprintf(f, "repo.module-link=%s\n", repo->module_link);
         if (repo->section)
                 fprintf(f, "repo.section=%s\n", repo->section);
         if (repo->clone_url)
                 fprintf(f, "repo.clone-url=%s\n", repo->clone_url);
         fprintf(f, "repo.enable-commit-graph=%d\n",
                 repo->enable_commit_graph);
         fprintf(f, "repo.enable-log-filecount=%d\n",
                 repo->enable_log_filecount);
         fprintf(f, "repo.enable-log-linecount=%d\n",
                 repo->enable_log_linecount);
         if (repo->about_filter && repo->about_filter != ctx.cfg.about_filter)
                 fprintf(f, "repo.about-filter=%s\n", repo->about_filter->cmd);
         if (repo->commit_filter && repo->commit_filter != ctx.cfg.commit_filter)
                 fprintf(f, "repo.commit-filter=%s\n", repo->commit_filter->cmd);
         if (repo->source_filter && repo->source_filter != ctx.cfg.source_filter)
                 fprintf(f, "repo.source-filter=%s\n", repo->source_filter->cmd);
         if (repo->snapshots != ctx.cfg.snapshots) {
                 char *tmp = build_snapshot_setting(repo->snapshots);
                 fprintf(f, "repo.snapshots=%s\n", tmp);
                 free(tmp);
         }
         if (repo->max_stats != ctx.cfg.max_stats)
                 fprintf(f, "repo.max-stats=%s\n",
                         cgit_find_stats_periodname(repo->max_stats));
         fprintf(f, "\n");
 }
 
 void print_repolist(FILE *f, struct cgit_repolist *list, int start)
 {
         int i;
 
         for(i = start; i < list->count; i++)
                 print_repo(f, &list->repos[i]);
 }
 
 /* Scan 'path' for git repositories, save the resulting repolist in 'cached_rc'
  * and return 0 on success.
  */
 static int generate_cached_repolist(const char *path, const char *cached_rc)
 {
         char *locked_rc;
         int idx;
         FILE *f;
 
         locked_rc = xstrdup(fmt("%s.lock", cached_rc));
         f = fopen(locked_rc, "wx");
         if (!f) {
                 /* Inform about the error unless the lockfile already existed,
                  * since that only means we've got concurrent requests.
                  */
                 if (errno != EEXIST)
                         fprintf(stderr, "[cgit] Error opening %s: %s (%d)\n",
                                 locked_rc, strerror(errno), errno);
                 return errno;
         }
         idx = cgit_repolist.count;
         if (ctx.cfg.project_list)
                 scan_projects(path, ctx.cfg.project_list, repo_config);
         else
                 scan_tree(path, repo_config);
         print_repolist(f, &cgit_repolist, idx);
         if (rename(locked_rc, cached_rc))
                 fprintf(stderr, "[cgit] Error renaming %s to %s: %s (%d)\n",
                         locked_rc, cached_rc, strerror(errno), errno);
         fclose(f);
         return 0;
 }
 
 static void process_cached_repolist(const char *path)
 {
         struct stat st;
         char *cached_rc;
         time_t age;
         unsigned long hash;
 
         hash = hash_str(path);
         if (ctx.cfg.project_list)
                 hash += hash_str(ctx.cfg.project_list);
         cached_rc = xstrdup(fmt("%s/rc-%8lx", ctx.cfg.cache_root, hash));
 
         if (stat(cached_rc, &st)) {
                 /* Nothing is cached, we need to scan without forking. And
                  * if we fail to generate a cached repolist, we need to
                  * invoke scan_tree manually.
                  */
                 if (generate_cached_repolist(path, cached_rc)) {
                         if (ctx.cfg.project_list)
                                 scan_projects(path, ctx.cfg.project_list,
                                               repo_config);
                         else
                                 scan_tree(path, repo_config);
                 }
                 return;
         }
 
         parse_configfile(cached_rc, config_cb);
 
         /* If the cached configfile hasn't expired, lets exit now */
         age = time(NULL) - st.st_mtime;
         if (age <= (ctx.cfg.cache_scanrc_ttl * 60))
                 return;
 
         /* The cached repolist has been parsed, but it was old. So lets
          * rescan the specified path and generate a new cached repolist
          * in a child-process to avoid latency for the current request.
          */
         if (fork())
                 return;
 
         exit(generate_cached_repolist(path, cached_rc));
 }
 
 static void cgit_parse_args(int argc, const char **argv)
 {
         int i;
         int scan = 0;
 
         for (i = 1; i < argc; i++) {
                 if (!strncmp(argv[i], "--cache=", 8)) {
                         ctx.cfg.cache_root = xstrdup(argv[i]+8);
                 }
                 if (!strcmp(argv[i], "--nocache")) {
                         ctx.cfg.nocache = 1;
                 }
                 if (!strcmp(argv[i], "--nohttp")) {
                         ctx.env.no_http = "1";
                 }
                 if (!strncmp(argv[i], "--query=", 8)) {
                         ctx.qry.raw = xstrdup(argv[i]+8);
                 }
                 if (!strncmp(argv[i], "--repo=", 7)) {
                         ctx.qry.repo = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--page=", 7)) {
                         ctx.qry.page = xstrdup(argv[i]+7);
                 }
                 if (!strncmp(argv[i], "--head=", 7)) {
                         ctx.qry.head = xstrdup(argv[i]+7);
                         ctx.qry.has_symref = 1;
                 }
                 if (!strncmp(argv[i], "--sha1=", 7)) {
                         ctx.qry.sha1 = xstrdup(argv[i]+7);
                         ctx.qry.has_sha1 = 1;
                 }
                 if (!strncmp(argv[i], "--ofs=", 6)) {
                         ctx.qry.ofs = atoi(argv[i]+6);
                 }
                 if (!strncmp(argv[i], "--scan-tree=", 12) ||
                     !strncmp(argv[i], "--scan-path=", 12)) {
                         /* HACK: the global snapshot bitmask defines the
                          * set of allowed snapshot formats, but the config
                          * file hasn't been parsed yet so the mask is
                          * currently 0. By setting all bits high before
                          * scanning we make sure that any in-repo cgitrc
                          * snapshot setting is respected by scan_tree().
                          * BTW: we assume that there'll never be more than
                          * 255 different snapshot formats supported by cgit...
                          */
                         ctx.cfg.snapshots = 0xFF;
                         scan++;
                         scan_tree(argv[i] + 12, repo_config);
                 }
         }
         if (scan) {
                 qsort(cgit_repolist.repos, cgit_repolist.count,
                         sizeof(struct cgit_repo), cmp_repos);
                 print_repolist(stdout, &cgit_repolist, 0);
                 exit(0);
         }
 }
 
 static int calc_ttl()
 {
         if (!ctx.repo)
                 return ctx.cfg.cache_root_ttl;
 
         if (!ctx.qry.page)
                 return ctx.cfg.cache_repo_ttl;
 
         if (ctx.qry.has_symref)
                 return ctx.cfg.cache_dynamic_ttl;
 
         if (ctx.qry.has_sha1)
                 return ctx.cfg.cache_static_ttl;
 
         return ctx.cfg.cache_repo_ttl;
 }
 
 int main(int argc, const char **argv)
 {
         const char *path;
         char *qry;
         int err, ttl;
 
         prepare_context(&ctx);
         cgit_repolist.length = 0;
         cgit_repolist.count = 0;
         cgit_repolist.repos = NULL;
 
         cgit_parse_args(argc, argv);
         parse_configfile(expand_macros(ctx.env.cgit_config), config_cb);
         ctx.repo = NULL;
         http_parse_querystring(ctx.qry.raw, querystring_cb);
 
         /* If virtual-root isn't specified in cgitrc, lets pretend
          * that virtual-root equals SCRIPT_NAME, minus any possibly
          * trailing slashes.
          */
         if (!ctx.cfg.virtual_root && ctx.cfg.script_name) {
                 ctx.cfg.virtual_root = trim_end(ctx.cfg.script_name, '/');
                 if (!ctx.cfg.virtual_root)
                         ctx.cfg.virtual_root = "";
         }
 
         /* If no url parameter is specified on the querystring, lets
          * use PATH_INFO as url. This allows cgit to work with virtual
          * urls without the need for rewriterules in the webserver (as
          * long as PATH_INFO is included in the cache lookup key).
          */
         path = ctx.env.path_info;
         if (!ctx.qry.url && path) {
                 if (path[0] == '/')
                         path++;
                 ctx.qry.url = xstrdup(path);
                 if (ctx.qry.raw) {
                         qry = ctx.qry.raw;
                         ctx.qry.raw = xstrdup(fmt("%s?%s", path, qry));
                         free(qry);
                 } else
                         ctx.qry.raw = xstrdup(ctx.qry.url);
                 cgit_parse_url(ctx.qry.url);
         }
 
         ttl = calc_ttl();
         ctx.page.expires += ttl*60;
         if (ctx.env.request_method && !strcmp(ctx.env.request_method, "HEAD"))
                 ctx.cfg.nocache = 1;
         if (ctx.cfg.nocache)
                 ctx.cfg.cache_size = 0;
         err = cache_process(ctx.cfg.cache_size, ctx.cfg.cache_root,
                             ctx.qry.raw, ttl, process_request, &ctx);
         if (err)
                 cgit_print_error(fmt("Error processing page: %s (%d)",
                                      strerror(err), err));
         return err;
 }