Fix rule recognition at beginning of buffer

2 files changed, 12 insertions, 3 deletions

diff --git a/snakemake-mode.el b/snakemake-mode.el
index 2e40b7b..368c4c3 100644
--- a/snakemake-mode.el
+++ b/snakemake-mode.el
@@ -229,9 +229,11 @@ Indent according the the first case below that is true.
       (when (funcall blank-p)
         (forward-line -1))
       (catch 'in-block
-        (while (not (or (bobp) (funcall blank-p)))
-          (when (looking-at-p snakemake-rule-or-subworkflow-re)
-            (throw 'in-block t))
+        (while (not (funcall blank-p))
+          (cond ((looking-at-p snakemake-rule-or-subworkflow-re)
+                 (throw 'in-block t))
+                ((bobp)
+                 (throw 'in-block nil)))
           (forward-line -1))))))
 
 (defun snakemake-below-naked-field-p ()
diff --git a/snakemake-test.el b/snakemake-test.el
index 880d7d5..8ebb3ff 100644
--- a/snakemake-test.el
+++ b/snakemake-test.el
@@ -522,6 +522,13 @@ rule abc:
     output: 'file'"
     (should-not (snakemake-in-rule-or-subworkflow-block-p)))
 
+  ;; At beginning of buffer
+  (snakemake-with-temp-text
+      "\
+rule abc:
+    output: 'file'<point>"
+    (should (snakemake-in-rule-or-subworkflow-block-p)))
+
   ;; Subworkflow
   (snakemake-with-temp-text
       "