fix anchor extraction and operation parsing to handle payload lines

- avoid processing payload and comment lines via filter.
- add guard on short strings (2 and under) just in case.
- fixed args-out-of-range crash when payload lines appeared in patches.

1 files changed, 57 insertions, 48 deletions

diff --git a/llm-tools-hl.el b/llm-tools-hl.el
index d745953..b095a6e 100644
--- a/llm-tools-hl.el
+++ b/llm-tools-hl.el
@@ -160,19 +160,19 @@ single string."
 (defun llm-tools--hl-validate-insert-has-payload (ops)
   "Check that all insert ops have at least one payload line."
   (mapcan (lambda (op)
-          (when (and (memq (hl-verify-op-type op) '(insert-after insert-before))
-                     (null (hl-verify-op-payload op)))
-            (list (format "Insert operation (%s) has no payload lines following it"
-                          (hl-verify-op-type op)))))
+            (when (and (memq (hl-verify-op-type op) '(insert-after insert-before))
+                       (null (hl-verify-op-payload op)))
+              (list (format "Insert operation (%s) has no payload lines following it"
+                            (hl-verify-op-type op)))))
           ops))
 
 (defun llm-tools--hl-validate-delete-no-payload (ops)
   "Check that delete ops have no payload lines."
   (mapcan (lambda (op)
-          (when (and (eq (hl-verify-op-type op) 'delete)
-                     (hl-verify-op-payload op))
-            (list "Delete operation (-) must not have payload lines")))
-        ops))
+            (when (and (eq (hl-verify-op-type op) 'delete)
+                       (hl-verify-op-payload op))
+              (list "Delete operation (-) must not have payload lines")))
+          ops))
 
 (defun llm-tools--hl-validate-insert-anchor (anchor)
   "Return error string if ANCHOR is malformed for insert, else nil."
@@ -199,14 +199,14 @@ single string."
 (defun llm-tools--hl-validate-anchors (ops)
   "Check that all anchors are well-formed."
   (mapcan (lambda (op)
-          (pcase (hl-verify-op-type op)
-            ((or 'insert-after 'insert-before)
-             (when-let ((err (llm-tools--hl-validate-insert-anchor (hl-verify-op-anchor op))))
-               (list err)))
-            ((or 'delete 'replace)
-             (when-let ((err (llm-tools--hl-validate-range-anchor (hl-verify-op-anchor op))))
-               (list err)))))
-        ops))
+            (pcase (hl-verify-op-type op)
+              ((or 'insert-after 'insert-before)
+               (when-let ((err (llm-tools--hl-validate-insert-anchor (hl-verify-op-anchor op))))
+                 (list err)))
+              ((or 'delete 'replace)
+               (when-let ((err (llm-tools--hl-validate-range-anchor (hl-verify-op-anchor op))))
+                 (list err)))))
+          ops))
 
 (defun llm-tools--hl-verify-section (section)
   "Validate a single SECTION. Returns a list of error strings."
@@ -275,7 +275,7 @@ and the cdr is the remainder of that section."
 (defun llm-tools--hl-extract-anchors-from-op-line (line)
   "Return a list of anchor strings from a single operation LINE.
 Handles ranges by returning both endpoints."
-  (when (length> line 0)
+  (when (and (stringp line) (length> line 2))
     (let ((op (char-to-string (elt line 0)))
           (anchor (substring line 2)))
       (pcase op
@@ -283,10 +283,18 @@ Handles ranges by returning both endpoints."
         ((or "-" "=") (split-string anchor "\\.\\."))))))
 
 (defun llm-tools--hl-extract-anchors-from-section (section-body)
-  "Return all anchors from a section body (list of strings)."
-  (flatten-list
-   (mapcar #'llm-tools--hl-extract-anchors-from-op-line
-           (string-lines section-body))))
+  "Return all anchors from a section body (string).
+Only lines starting with +, <, -, or = are considered."
+  (let ((ops-lines
+         (cl-remove-if-not
+          (lambda (line)
+            (let ((trimmed (string-trim line)))
+              (and (not (string-empty-p trimmed))
+                   (not (string-prefix-p "#" trimmed))
+                   (not (string-prefix-p "~" trimmed))
+                   (member (substring trimmed 0 1) '("+" "<" "-" "=")))))
+          (string-lines section-body))))
+    (flatten-list (mapcar #'llm-tools--hl-extract-anchors-from-op-line ops-lines))))
 
 (defun llm-tools--hl-get-anchors (patch)
   "Returns an alist of (FILENAME . ANCHORS) from PATCH.
@@ -326,39 +334,40 @@ line in the on-disk file."
   (string-to-number (substring anchor 0 (- (length anchor) 2))))
 
 (defun llm-tools--hl-parse-op-line (line)
-  "Parse a single operation LINE into a `hl-op` struct.
-LINE should start with `+`, `<`, `-`, or `=`."
-  (pcase (substring line 0 1)
-    ("+"
-     (make-hl-op :type 'insert-after
-                 :anchor (substring line 2)))
-    ("<"
-     (make-hl-op :type 'insert-before
-                 :anchor (substring line 2)))
-    ("-"
-     (make-hl-op :type 'delete
-                 :range (split-string (substring line 2) "\\.\\.")))
-    ("="
-     (make-hl-op :type 'replace
-                 :range (split-string (substring line 2) "\\.\\.")))))
+  "Parse a single operation LINE into an `hl-op` struct.
+LINE must start with `+`, `<`, `-`, or `=`, followed by a space,
+followed by an anchor (or range)."
+  (string-match "^[+<=-] \\(.*\\)" line)  ; returns index or nil
+  (unless (match-beginning 0)
+    (error "Invalid operation line: %S" line))
+  (let* ((op-char (substring line 0 1))
+         (anchor (match-string 1 line)))
+    (pcase op-char
+      ("+" (make-hl-op :type 'insert-after :anchor anchor))
+      ("<" (make-hl-op :type 'insert-before :anchor anchor))
+      ("-" (make-hl-op :type 'delete :range (split-string anchor "\\.\\.")))
+      ("=" (make-hl-op :type 'replace :range (split-string anchor "\\.\\."))))))
 
 (defun llm-tools--hl-parse-section (section)
   "Parse SECTION (body after `@@ PATH`) into a list of `hl-op` structs.
 Skips comment lines (starting with `#`) and blank lines."
   (let (ops op)
     (dolist (line (string-lines section))
-      (when (string-match "\\S-" line)
-        (let ((op-char (substring line 0 1)))
-          (pcase op-char
-            ("~"
-             (when op
-               (setf (hl-op-payload op)
-                     (append (hl-op-payload op)
-                             (list (substring line 1))))))
-            ("#" nil)
-            (_
-             (when op (push op ops))
-             (setq op (llm-tools--hl-parse-op-line line)))))))
+      (let ((trimmed (string-trim-left line)))
+        (when (string-match "\\S-" trimmed)
+          (let ((op-char (substring trimmed 0 1)))
+            (pcase op-char
+              ("~"
+               (when op
+                 (setf (hl-op-payload op)
+                       (append (hl-op-payload op)
+                               (list (substring trimmed 1))))))
+              ("#" nil)
+              (_
+               (when op (push op ops))
+               (if (< (length trimmed) 3)
+                   (error "Malformed operation line (too short): %S" trimmed))
+               (setq op (llm-tools--hl-parse-op-line trimmed))))))))
     (when op (push op ops))
     (nreverse ops)))