[PATCH] Rename and extend read_tree_with_tree_or_commit_sha1

[git.git] / sha1_file.c

diff --git a/sha1_file.c b/sha1_file.c
index db2880e..29f48d5 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -189,44 +189,49 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
        return NULL;
 }
 
-void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
-                                        unsigned long *size,
-                                        unsigned char *tree_sha1_return)
+void *read_object_with_reference(const unsigned char *sha1,
+                                const unsigned char *required_type,
+                                unsigned long *size,
+                                unsigned char *actual_sha1_return)
 {
        char type[20];
        void *buffer;
        unsigned long isize;
-       int was_commit = 0;
-       unsigned char tree_sha1[20];
-
-       buffer = read_sha1_file(sha1, type, &isize);
-
-       /* 
-        * We might have read a commit instead of a tree, in which case
-        * we parse out the tree_sha1 and attempt to read from there.
-        * (buffer + 5) is because the tree sha1 is always at offset 5
-        * in a commit record ("tree ").
-        */
-       if (buffer &&
-           !strcmp(type, "commit") &&
-           !get_sha1_hex(buffer + 5, tree_sha1)) {
-               free(buffer);
-               buffer = read_sha1_file(tree_sha1, type, &isize);
-               was_commit = 1;
-       }
+       unsigned char actual_sha1[20];
 
-       /*
-        * Now do we have something and if so is it a tree?
-        */
-       if (!buffer || strcmp(type, "tree")) {
-               free(buffer);
-               return NULL;
-       }
+       memcpy(actual_sha1, sha1, 20);
+       while (1) {
+               int ref_length = -1;
+               const char *ref_type = NULL;
 
-       *size = isize;
-       if (tree_sha1_return)
-               memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
-       return buffer;
+               buffer = read_sha1_file(actual_sha1, type, &isize);
+               if (!buffer)
+                       return NULL;
+               if (!strcmp(type, required_type)) {
+                       *size = isize;
+                       if (actual_sha1_return)
+                               memcpy(actual_sha1_return, actual_sha1, 20);
+                       return buffer;
+               }
+               /* Handle references */
+               else if (!strcmp(type, "commit"))
+                       ref_type = "tree ";
+               else if (!strcmp(type, "tag"))
+                       ref_type = "object ";
+               else {
+                       free(buffer);
+                       return NULL;
+               }
+               ref_length = strlen(ref_type);
+
+               if (memcmp(buffer, ref_type, ref_length) ||
+                   get_sha1_hex(buffer + ref_length, actual_sha1)) {
+                       free(buffer);
+                       return NULL;
+               }
+               /* Now we have the ID of the referred-to object in
+                * actual_sha1.  Check again. */
+       }
 }
 
 int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)