From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Tue, 14 Nov 2017 12:37:32 +0000 (+0000)
Subject: Update cursor logic for empty lists
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26afe2bc6c2a578cf82dddbcdd19ecfbd15aa9dc;p=thirdparty%2Ffreeradius-server.git

Update cursor logic for empty lists

Appending, prepending, inserting, replacing on an empty list should not set current.  That way fr_cursor_next() produces a consistent result on empty lists and populated lists when we're using cursors to track progress.
---

diff --git a/src/lib/util/cursor.c b/src/lib/util/cursor.c
index fb21d1fde1c..7c5c9eb2ec8 100644
--- a/src/lib/util/cursor.c
+++ b/src/lib/util/cursor.c
@@ -257,8 +257,6 @@ void CC_HINT(hot) fr_cursor_prepend(fr_cursor_t *cursor, void *v)
 
 		*NEXT_PTR(v) = NULL;				/* Only insert one at a time */
 
-		fr_cursor_next(cursor);				/* Update current */
-
 		return;
 	}
 
@@ -292,8 +290,6 @@ void CC_HINT(hot) fr_cursor_append(fr_cursor_t *cursor, void *v)
 		*cursor->head = v;
 		*NEXT_PTR(v) = NULL;				/* Only insert one at a time */
 
-		fr_cursor_next(cursor);				/* Update current */
-
 		return;
 	}
 
@@ -771,7 +767,8 @@ void test_cursor_append_empty(void)
 	fr_cursor_append(&cursor, &item1);
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next_peek(&cursor) == &item1);
 	TEST_CHECK(fr_cursor_list_prev_peek(&cursor) == NULL);
 }
 
@@ -790,7 +787,8 @@ void test_cursor_append_empty_3(void)
 	fr_cursor_append(&cursor, &item3);
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next(&cursor) == &item1);
 	TEST_CHECK(fr_cursor_next(&cursor) == &item2);
 	TEST_CHECK(fr_cursor_tail(&cursor) == &item3);
 }
@@ -806,7 +804,8 @@ void test_cursor_prepend_empty(void)
 	fr_cursor_prepend(&cursor, &item1);
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next_peek(&cursor) == &item1);
 	TEST_CHECK(fr_cursor_list_prev_peek(&cursor) == NULL);
 }
 
@@ -821,7 +820,8 @@ void test_cursor_insert_into_empty(void)
 	fr_cursor_insert(&cursor, &item1);
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next_peek(&cursor) == &item1);
 	TEST_CHECK(fr_cursor_list_prev_peek(&cursor) == NULL);
 }
 
@@ -840,9 +840,10 @@ void test_cursor_insert_into_empty_3(void)
 	fr_cursor_insert(&cursor, &item3);
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
-	TEST_CHECK(fr_cursor_next(&cursor) == &item3);
-	TEST_CHECK(fr_cursor_tail(&cursor) == &item2);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next(&cursor) == &item1);
+	TEST_CHECK(fr_cursor_next(&cursor) == &item2);
+	TEST_CHECK(fr_cursor_tail(&cursor) == &item3);
 }
 
 void test_cursor_replace_in_empty(void)
@@ -856,7 +857,8 @@ void test_cursor_replace_in_empty(void)
 	TEST_CHECK(!fr_cursor_replace(&cursor, &item1));
 
 	item_p = fr_cursor_current(&cursor);
-	TEST_CHECK(item_p == &item1);
+	TEST_CHECK(!item_p);
+	TEST_CHECK(fr_cursor_next_peek(&cursor) == &item1);
 	TEST_CHECK(fr_cursor_list_prev_peek(&cursor) == NULL);
 }
 
@@ -1665,9 +1667,9 @@ void test_cursor_free(void)
 	fr_cursor_list_free(&cursor);
 
 	TEST_CHECK(fr_cursor_current(&cursor) == NULL);
-	TEST_CHECK(fr_cursor_list_prev_peek(&cursor) == item1);
-	TEST_CHECK(fr_cursor_tail(&cursor) == item1);
-	TEST_CHECK(fr_cursor_head(&cursor) == item1);
+	TEST_CHECK(!fr_cursor_list_prev_peek(&cursor));
+	TEST_CHECK(!fr_cursor_tail(&cursor));
+	TEST_CHECK(!fr_cursor_head(&cursor));
 
 	item_p = fr_cursor_remove(&cursor);
 	talloc_free(item_p);
diff --git a/src/lib/util/strerror.c b/src/lib/util/strerror.c
index 8ac011459ab..5ab3a72ceea 100644
--- a/src/lib/util/strerror.c
+++ b/src/lib/util/strerror.c
@@ -216,6 +216,7 @@ char const *fr_strerror(void)
 	buffer = fr_strerror_buffer;
 	if (!buffer) return "";
 
+	fr_cursor_head(&buffer->cursor);
 	entry = fr_cursor_remove(&buffer->cursor);
 	if (!entry) return "";
 
diff --git a/src/main/xlat_eval.c b/src/main/xlat_eval.c
index 3ce3ea6646c..e0e76efce54 100644
--- a/src/main/xlat_eval.c
+++ b/src/main/xlat_eval.c
@@ -197,7 +197,7 @@ static xlat_action_t xlat_eval_one_letter(TALLOC_CTX *ctx, fr_cursor_t *out, REQ
 		return XLAT_ACTION_FAIL;
 	}
 
-	fr_cursor_insert(out, value);
+	fr_cursor_append(out, value);
 	return XLAT_ACTION_DONE;
 }
 
@@ -529,7 +529,7 @@ static char *xlat_aprint(TALLOC_CTX *ctx, REQUEST *request, xlat_exp_t const * c
 	case XLAT_ATTRIBUTE:
 		if (xlat_eval_pair(ctx, &cursor, request, node->attr) == XLAT_ACTION_FAIL) return NULL;
 
-		value = fr_cursor_current(&cursor);
+		value = fr_cursor_head(&cursor);
 		if (!value) return NULL;
 
 		/*
diff --git a/src/modules/rlm_expr/rlm_expr.c b/src/modules/rlm_expr/rlm_expr.c
index 6b290bab2f6..d40df232a2d 100644
--- a/src/modules/rlm_expr/rlm_expr.c
+++ b/src/modules/rlm_expr/rlm_expr.c
@@ -1528,6 +1528,7 @@ static ssize_t explode_xlat(TALLOC_CTX *ctx, char **out, size_t outlen,
 	    	vp = fr_cursor_next(&cursor);
 	}
 
+	fr_cursor_head(&to_merge);
 	fr_cursor_merge(&cursor, &to_merge);
 	talloc_free(vpt);