5 files changed, 95 insertions, 31 deletions

diff --git a/cgit.c b/cgit.c
index 04682be..f738b83 100644
--- a/cgit.c
+++ b/cgit.c
@@ -14,6 +14,8 @@
 #include "html.h"
 #include "ui-shared.h"
 #include "ui-stats.h"
+#include "ui-blob.h"
+#include "ui-summary.h"
 #include "scan-tree.h"
 
 const char *cgit_version = CGIT_VERSION;
@@ -469,6 +471,38 @@ static char *guess_defbranch(void)
 	return xstrdup(ref + 11);
 }
 
+static void choose_readme(struct cgit_repo *repo)
+{
+	char *entry, *filename, *ref;
+
+	/* If there's no space, we skip the possibly expensive
+	 * selection process. */
+	if (!repo->readme || !strchr(repo->readme, ' '))
+		return;
+
+	for (entry = strtok(repo->readme, " "); entry; entry = strtok(NULL, " ")) {
+		cgit_parse_readme(entry, NULL, &filename, &ref, repo);
+		if (!(*filename)) {
+			free(filename);
+			free(ref);
+			continue;
+		}
+		if (*ref && cgit_ref_path_exists(filename, ref)) {
+			free(filename);
+			free(ref);
+			break;
+		}
+		if (!access(filename, R_OK)) {
+			free(filename);
+			free(ref);
+			break;
+		}
+		free(filename);
+		free(ref);
+	}
+	repo->readme = entry;
+}
+
 static int prepare_repo_cmd(struct cgit_context *ctx)
 {
 	unsigned char sha1[20];
@@ -537,6 +571,7 @@ static int prepare_repo_cmd(struct cgit_context *ctx)
 	}
 	sort_string_list(&ctx->repo->submodules);
 	cgit_prepare_repo_env(ctx->repo);
+	choose_readme(ctx->repo);
 	return 0;
 }
 
diff --git a/ui-blob.c b/ui-blob.c
index 8f6989f..b4be139 100644
--- a/ui-blob.c
+++ b/ui-blob.c
@@ -13,7 +13,7 @@
 #include "ui-shared.h"
 
 struct walk_tree_context {
-	char *match_path;
+	const char *match_path;
 	unsigned char *matched_sha1;
 	int found_path;
 };
@@ -31,6 +31,32 @@ static int walk_tree(const unsigned char *sha1, const char *base, int baselen,
 	return 0;
 }
 
+int cgit_ref_path_exists(const char *path, const char *ref)
+{
+        unsigned char sha1[20];
+        unsigned long size;
+        struct pathspec_item path_items = {
+                .match = path,
+                .len = strlen(path)
+        };
+        struct pathspec paths = {
+                .nr = 1,
+                .items = &path_items
+        };
+        struct walk_tree_context walk_tree_ctx = {
+                .match_path = path,
+                .matched_sha1 = sha1,
+                .found_path = 0
+        };
+
+        if (get_sha1(ref, sha1))
+                return 0;
+        if (sha1_object_info(sha1, &size) != OBJ_COMMIT) 
+                return 0;
+        read_tree_recursive(lookup_commit_reference(sha1)->tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+        return walk_tree_ctx.found_path;
+}
+
 int cgit_print_file(char *path, const char *head)
 {
 	unsigned char sha1[20];
diff --git a/ui-blob.h b/ui-blob.h
index d7e7d45..ce3649f 100644
--- a/ui-blob.h
+++ b/ui-blob.h
@@ -1,6 +1,7 @@
 #ifndef UI_BLOB_H
 #define UI_BLOB_H
 
+extern int cgit_ref_path_exists(const char *path, const char *ref);
 extern int cgit_print_file(char *path, const char *head);
 extern void cgit_print_blob(const char *hex, char *path, const char *head);
 
diff --git a/ui-summary.c b/ui-summary.c
index ffad4f2..2f8a822 100644
--- a/ui-summary.c
+++ b/ui-summary.c
@@ -95,70 +95,71 @@ void cgit_print_summary()
 	html("</table>");
 }
 
-void cgit_print_repo_readme(char *path)
+/* The caller must free filename and ref after calling this. */
+void cgit_parse_readme(const char *readme, const char *path, char **filename, char **ref, struct cgit_repo *repo)
 {
-	char *slash, *tmp, *colon, *ref;
-	int free_filename = 0;
+	const char *slash, *colon;
 
-	if (!ctx.repo->readme || !(*ctx.repo->readme))
-		return;
+	*filename = NULL;
+	*ref = NULL;
 
-	ref = NULL;
+	if (!readme || !(*readme))
+		return;
 
 	/* Check if the readme is tracked in the git repo. */
-	colon = strchr(ctx.repo->readme, ':');
+	colon = strchr(readme, ':');
 	if (colon && strlen(colon) > 1) {
-		*colon = '\0';
 		/* If it starts with a colon, we want to use
 		 * the default branch */
-		if (colon == ctx.repo->readme && ctx.repo->defbranch)
-			ref = ctx.repo->defbranch;
+		if (colon == readme && repo->defbranch)
+			*ref = xstrdup(repo->defbranch);
 		else
-			ref = ctx.repo->readme;
-		ctx.repo->readme = colon + 1;
-		if (!(*ctx.repo->readme))
-			return;
+			*ref = xstrndup(readme, colon - readme);
+		readme = colon + 1;
 	}
 
 	/* Prepend repo path to relative readme path unless tracked. */
-	if (!ref && *ctx.repo->readme != '/')
-		ctx.repo->readme = fmtalloc("%s/%s", ctx.repo->path,
-						ctx.repo->readme);
+	if (!(*ref) && *readme != '/')
+		readme = fmtalloc("%s/%s", repo->path, readme);
 
 	/* If a subpath is specified for the about page, make it relative
-	 * to the directory containing the configured readme.
-	 */
+	 * to the directory containing the configured readme. */
 	if (path) {
-		slash = strrchr(ctx.repo->readme, '/');
+		slash = strrchr(readme, '/');
 		if (!slash) {
 			if (!colon)
 				return;
 			slash = colon;
 		}
-		free_filename = 1;
-		tmp = xmalloc(slash - ctx.repo->readme + 1 + strlen(path) + 1);
-		strncpy(tmp, ctx.repo->readme, slash - ctx.repo->readme + 1);
-		strcpy(tmp + (slash - ctx.repo->readme + 1), path);
+		*filename = xmalloc(slash - readme + 1 + strlen(path) + 1);
+		strncpy(*filename, readme, slash - readme + 1);
+		strcpy(*filename + (slash - readme + 1), path);
 	} else
-		tmp = ctx.repo->readme;
+		*filename = xstrdup(readme);
+}
+
+void cgit_print_repo_readme(char *path)
+{
+	char *filename, *ref;
+	cgit_parse_readme(ctx.repo->readme, path, &filename, &ref, ctx.repo);
 
 	/* Print the calculated readme, either from the git repo or from the
 	 * filesystem, while applying the about-filter.
 	 */
 	html("<div id='summary'>");
 	if (ctx.repo->about_filter) {
-		ctx.repo->about_filter->argv[1] = tmp;
+		ctx.repo->about_filter->argv[1] = filename;
 		cgit_open_filter(ctx.repo->about_filter);
 	}
 	if (ref)
-		cgit_print_file(tmp, ref);
+		cgit_print_file(filename, ref);
 	else
-		html_include(tmp);
+		html_include(filename);
 	if (ctx.repo->about_filter) {
 		cgit_close_filter(ctx.repo->about_filter);
 		ctx.repo->about_filter->argv[1] = NULL;
 	}
 	html("</div>");
-	if (free_filename)
-		free(tmp);
+	free(filename);
+	free(ref);
 }
diff --git a/ui-summary.h b/ui-summary.h
index c01f560..d6dc5ba 100644
--- a/ui-summary.h
+++ b/ui-summary.h
@@ -1,6 +1,7 @@
 #ifndef UI_SUMMARY_H
 #define UI_SUMMARY_H
 
+extern void cgit_parse_readme(const char *readme, const char *path, char **filename, char **ref, struct cgit_repo *repo);
 extern void cgit_print_summary();
 extern void cgit_print_repo_readme(char *path);