Change blob API to return temp refs to the content

If the user wants permanent references, he can duplicate the temporary
one manually.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

src/blob.c

@@ -30,35 +30,20 @@
 #include "common.h"
 #include "blob.h"
 
-int git_blob_rawcontent(git_blob *blob, void *buffer, size_t len)
+const char *git_blob_rawcontent(git_blob *blob)
 {
-	int error;
-
-	assert(blob && buffer);
-	
-	if (blob->content.data != NULL) {
-
-		if (len + 1 < blob->content.len)
-			return GIT_ENOMEM;
-	
-		memcpy(buffer, blob->content.data, blob->content.len);
-		((char *)buffer)[blob->content.len] = 0;
-	
-	} else {
-
-		if (len + 1 < blob->object.source.raw.len)
-			return GIT_ENOMEM;
+	assert(blob);
 	
-		if ((error = git_object__source_open((git_object *)blob)) < 0)
-			return error;
+	if (blob->content.data != NULL)
+		return blob->content.data;
 
-		memcpy(buffer, blob->object.source.raw.data, blob->object.source.raw.len);
-		((char *)buffer)[blob->object.source.raw.len] = 0;
+	if (blob->object.in_memory)
+		return NULL;
 
-		git_object__source_close((git_object *)blob);
-	}
+	if (!blob->object.source.open && git_object__source_open((git_object *)blob) < 0)
+		return NULL;
 
-	return GIT_SUCCESS;
+	return blob->object.source.raw.data;
 }
 
 int git_blob_rawsize(git_blob *blob)
@@ -99,6 +84,8 @@ int git_blob_set_rawcontent(git_blob *blob, const void *buffer, size_t len)
 
 	blob->object.modified = 1;
 
+	git_object__source_close((git_object *)blob);
+
 	if (blob->content.data != NULL)
 		gitfo_free_buf(&blob->content);
 

src/git/blob.h

@@ -63,18 +63,17 @@ GIT_EXTERN(int) git_blob_set_rawcontent_fromfile(git_blob *blob, const char *fil
 GIT_EXTERN(int) git_blob_set_rawcontent(git_blob *blob, const void *buffer, size_t len);
 
 /**
- * Read the raw content of a blob.
+ * Get a read-only buffer with the raw content of a blob.
  *
- * A copy of the raw content is stored on the buffer passed
- * to the function. If the buffer is not long enough,
- * the method will fail.
+ * A pointer to the raw content of a blob is returned;
+ * this pointer is owned internally by the object and shall
+ * not be free'd. The pointer may be invalidated at a later
+ * time (e.g. when changing the contents of the blob).
  *
  * @param blob pointer to the blob
- * @param buffer buffer to fill with contents
- * @param len size of the buffer
- * @return 0 on success; error code otherwise
+ * @return the pointer; NULL if the blob has no contents
  */
-GIT_EXTERN(int) git_blob_rawcontent(git_blob *blob, void *buffer, size_t len);
+GIT_EXTERN(const char *) git_blob_rawcontent(git_blob *blob);
 
 /**
  * Get the size in bytes of the contents of a blob