allow blob extract blobs by head/path combination

 If blob is invoked with no id=, it tries to look up h= and search for path= in
 there. Once found, proceed as normal, otherwise, fail as normal.

Signed-off-by: Michael Krelin <hacker@klever.net>

3 files changed, 32 insertions, 3 deletions

diff --git a/cmd.c b/cmd.c
index 4edca6b..fe0ea8f 100644
--- a/cmd.c
+++ b/cmd.c
@@ -33,5 +33,5 @@ static void about_fn(struct cgit_context *ctx)
 static void blob_fn(struct cgit_context *ctx)
 {
-        cgit_print_blob(ctx->qry.sha1, ctx->qry.path);
+        cgit_print_blob(ctx->qry.sha1, ctx->qry.path, ctx->qry.head);
 }
 
diff --git a/ui-blob.c b/ui-blob.c
index ab44659..dd1bbce 100644
--- a/ui-blob.c
+++ b/ui-blob.c
@@ -11,5 +11,16 @@
 #include "ui-shared.h"
 
-void cgit_print_blob(const char *hex, char *path)
+static char *match_path;
+static unsigned char *matched_sha1;
+
+static int walk_tree(const unsigned char *sha1, const char *base,int baselen, const char *pathname, unsigned mode, int stage) {
+        if(strncmp(base,match_path,baselen)
+                || strcmp(match_path+baselen,pathname) )
+                return READ_TREE_RECURSIVE;
+        memmove(matched_sha1,sha1,20);
+        return 0;
+}
+
+void cgit_print_blob(const char *hex, char *path, const char *head)
 {
 
@@ -18,11 +29,29 @@ void cgit_print_blob(const char *hex, char *path)
         unsigned char *buf;
         unsigned long size;
+        struct commit *commit;
+        const char *paths[] = {path, NULL};
 
+        if (hex) {
         if (get_sha1_hex(hex, sha1)){
                 cgit_print_error(fmt("Bad hex value: %s", hex));
                 return;
         }
+        } else {
+                if (get_sha1(head,sha1)) {
+                        cgit_print_error(fmt("Bad ref: %s", head));
+                        return;
+                }
+        }
+
+        type = sha1_object_info(sha1, &size);
 
+        if((!hex) && type == OBJ_COMMIT && path) {
+                commit = lookup_commit_reference(sha1);
+                match_path = path;
+                matched_sha1 = sha1;
+                read_tree_recursive(commit->tree, NULL, 0, 0, paths, walk_tree);
         type = sha1_object_info(sha1, &size);
+        }
+
         if (type == OBJ_BAD) {
                 cgit_print_error(fmt("Bad object name: %s", hex));
diff --git a/ui-blob.h b/ui-blob.h
index 5a920a8..dad275a 100644
--- a/ui-blob.h
+++ b/ui-blob.h
@@ -2,5 +2,5 @@
 #define UI_BLOB_H
 
-extern void cgit_print_blob(const char *hex, char *path);
+extern void cgit_print_blob(const char *hex, char *path, const char *head);
 
 #endif /* UI_BLOB_H */