attr: support attr lookup by commit

Author: pmrowla

pygit2/__init__.py

@@ -94,6 +94,8 @@
 GIT_ATTR_CHECK_INDEX_THEN_FILE = C.GIT_ATTR_CHECK_INDEX_THEN_FILE
 GIT_ATTR_CHECK_INDEX_ONLY      = C.GIT_ATTR_CHECK_INDEX_ONLY
 GIT_ATTR_CHECK_NO_SYSTEM       = C.GIT_ATTR_CHECK_NO_SYSTEM
+GIT_ATTR_CHECK_INCLUDE_HEAD    = C.GIT_ATTR_CHECK_INCLUDE_HEAD
+GIT_ATTR_CHECK_INCLUDE_COMMIT  = C.GIT_ATTR_CHECK_INCLUDE_COMMIT
 
 # GIT_FETCH_PRUNE
 GIT_FETCH_PRUNE_UNSPECIFIED    = C.GIT_FETCH_PRUNE_UNSPECIFIED

pygit2/_run.py

@@ -54,8 +54,8 @@
 # Order matters
 h_files = [
     'types.h',
-    'attr.h',
     'oid.h',
+    'attr.h',
     'blame.h',
     'buffer.h',
     'strarray.h',

pygit2/decl/attr.h

@@ -1,7 +1,11 @@
 #define GIT_ATTR_CHECK_FILE_THEN_INDEX	0
 #define GIT_ATTR_CHECK_INDEX_THEN_FILE	1
 #define GIT_ATTR_CHECK_INDEX_ONLY		2
-#define GIT_ATTR_CHECK_NO_SYSTEM		4
+#define GIT_ATTR_CHECK_NO_SYSTEM        4
+#define GIT_ATTR_CHECK_INCLUDE_HEAD     8
+#define GIT_ATTR_CHECK_INCLUDE_COMMIT   16
+
+#define GIT_ATTR_OPTIONS_VERSION ...
 
 typedef enum {
 	GIT_ATTR_VALUE_UNSPECIFIED = 0, /**< The attribute has been left unspecified */
@@ -10,10 +14,17 @@ typedef enum {
 	GIT_ATTR_VALUE_STRING  /**< This attribute has a value */
 } git_attr_value_t;
 
-int git_attr_get(
+typedef struct {
+	unsigned int version;
+	unsigned int flags;
+	git_oid *commit_id;
+	git_oid attr_commit_id;
+} git_attr_options;
+
+int git_attr_get_ext(
 	const char **value_out,
 	git_repository *repo,
-	uint32_t flags,
+	git_attr_options *opts,
 	const char *path,
 	const char *name);
 

pygit2/repository.py

@@ -1371,7 +1371,7 @@ def ahead_behind(self, local, upstream):
     #
     # Git attributes
     #
-    def get_attr(self, path, name, flags=0):
+    def get_attr(self, path, name, flags=0, commit=None):
         """
         Retrieve an attribute for a file by path.
 
@@ -1391,6 +1391,10 @@ def get_attr(self, path, name, flags=0):
             A combination of `GIT_ATTR_CHECK_` flags which determine the
             lookup order.
 
+        commit
+            Optional id of commit to load attributes from when
+            `GIT_ATTR_CHECK_INCLUDE_COMMIT` is specified.
+
         Examples::
 
             >>> print(repo.get_attr('splash.bmp', 'binary'))
@@ -1401,8 +1405,16 @@ def get_attr(self, path, name, flags=0):
             'tab-in-indent,trailing-space'
         """
 
+        copts = ffi.new('git_attr_options *')
+        copts.version = C.GIT_ATTR_OPTIONS_VERSION
+        copts.flags = flags
+        if commit is not None:
+            if not isinstance(commit, Oid):
+                commit = Oid(hex=commit)
+            ffi.buffer(ffi.addressof(copts, 'attr_commit_id'))[:] = commit.raw
+
         cvalue = ffi.new('char **')
-        err = C.git_attr_get(cvalue, self._repo, flags, to_bytes(path), to_bytes(name))
+        err = C.git_attr_get_ext(cvalue, self._repo, copts, to_bytes(path), to_bytes(name))
         check_error(err)
 
         # Now let's see if we can figure out what the value is