Fix const-correctness of git_patch_get_delta, git_patch_num_hunks, git_patch_num_lines_in_hunk

include/git2/patch.h

@@ -141,12 +141,12 @@ GIT_EXTERN(void) git_patch_free(git_patch *patch);
 /**
  * Get the delta associated with a patch
  */
-GIT_EXTERN(const git_diff_delta *) git_patch_get_delta(git_patch *patch);
+GIT_EXTERN(const git_diff_delta *) git_patch_get_delta(const git_patch *patch);
 
 /**
  * Get the number of hunks in a patch
  */
-GIT_EXTERN(size_t) git_patch_num_hunks(git_patch *patch);
+GIT_EXTERN(size_t) git_patch_num_hunks(const git_patch *patch);
 
 /**
  * Get line counts of each type in a patch.
@@ -197,7 +197,7 @@ GIT_EXTERN(int) git_patch_get_hunk(
  * @return Number of lines in hunk or -1 if invalid hunk index
  */
 GIT_EXTERN(int) git_patch_num_lines_in_hunk(
-	git_patch *patch,
+	const git_patch *patch,
 	size_t hunk_idx);
 
 /**

src/diff_patch.c

@@ -631,13 +631,13 @@ void git_patch_free(git_patch *patch)
 		GIT_REFCOUNT_DEC(patch, diff_patch_free);
 }
 
-const git_diff_delta *git_patch_get_delta(git_patch *patch)
+const git_diff_delta *git_patch_get_delta(const git_patch *patch)
 {
 	assert(patch);
 	return patch->delta;
 }
 
-size_t git_patch_num_hunks(git_patch *patch)
+size_t git_patch_num_hunks(const git_patch *patch)
 {
 	assert(patch);
 	return git_array_size(patch->hunks);
@@ -708,7 +708,7 @@ int git_patch_get_hunk(
 	return 0;
 }
 
-int git_patch_num_lines_in_hunk(git_patch *patch, size_t hunk_idx)
+int git_patch_num_lines_in_hunk(const git_patch *patch, size_t hunk_idx)
 {
 	diff_patch_hunk *hunk;
 	assert(patch);