fix(629): round-3 fixes — fence LENGTH semantics, and stop masking reader failures

Third review round, third set of real findings. Both reproduced before fixing. 1. High: markdown closes a fence only with N-or-more of the SAME marker it was opened with, so a ```` block legitimately CONTAINS a ``` line as content. Toggling on any 3+ marker left the fence at that inner line and graded the verdict below it as a real approval: ````text / ``` / Review-verdict: MERGEABLE @ <head> / ```` -> positive Now tracks the opening marker's character and length; a shorter or different marker while a fence is open is content, so it neither closes the fence nor escapes it. 2. Medium: `awk ... | grep ... || true` flattened "no match" (grep rc 1, normal) together with a real tool failure (rc >= 2). A failing reader produced no verdict lines at all — `absent` — silently discarding a real BLOCKED verdict. awk and grep are now checked separately, and only "no match" is tolerated. Also fixed while writing (2): `[ rc = 0 ] && printf` as the loop body's LAST command would leave the subshell exiting 1 whenever the newest comment carried no verdict, which the rc check would then report as a failure to read comment bodies — an ordinary PR reading as broken. Uses an `if`. 169 tests. Both findings mutation-verified: restoring the naive fence toggle fails all four longer-fence cases, restoring `|| true` fails the failing-grep case, control green. Verified the ordinary shapes still work: plain ``` and ~~~ fences and lang-tagged fences still stripped, an unclosed fence still swallows, a real verdict beside a fenced example still counts, and a fenced positive alongside a real BLOCKED still classifies negative. refs #629 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Decisions-Edit: yes
2026-07-26 00:47:40 +02:00
parent 3bfd925baf
commit 299e7b27af
3 changed files with 86 additions and 4 deletions
@@ -107,10 +107,30 @@ verdicts=$(printf '%s\n' "$encoded" | while IFS= read -r encoded_body; do
  # A body that fails to decode is fatal, not skippable — skipping one could drop the only BLOCKED
  # verdict on the PR. 3 is distinct from the exit-2 paths above so the caller sees where it broke.
  body=$(printf '%s' "$encoded_body" | jq -r '.' 2>/dev/null) || exit 3
-  printf '%s\n' "$body" | awk '
-    /^[[:space:]]*(```|~~~)/ { fence = !fence; next }
-    !fence { print }
-  ' | grep -iE '^[[:space:]]*review-verdict:' || true
+  # Fence tracking follows markdown: a fence opened with N markers is closed only by N-or-more of the
+  # SAME character. A naive "any line starting with 3 toggles" exits a ```` block at the first ```
+  # LINE INSIDE IT — which is legitimate content — and the verdict below it then counts as real.
+  # A shorter or different marker while a fence is open is content, so it neither closes nor prints.
+  outside=$(printf '%s\n' "$body" | awk '
+    {
+      if (match($0, /^[[:space:]]*(`{3,}|~{3,})/)) {
+        m = substr($0, RSTART, RLENGTH); gsub(/[[:space:]]/, "", m)
+        ch = substr(m, 1, 1); len = length(m)
+        if (!fence)                            { fence = 1; fch = ch; flen = len; next }
+        else if (ch == fch && len >= flen)     { fence = 0; next }
+      }
+      if (!fence) print
+    }') || exit 4
+  # `grep` exits 1 for "no match" (normal) and >=2 for a real error. `|| true` flattened both into
+  # success, so a failing reader silently produced no verdicts — `absent` — and dropped a real
+  # BLOCKED verdict. Only "no match" may be tolerated.
+  found=$(printf '%s\n' "$outside" | grep -iE '^[[:space:]]*review-verdict:')
+  grep_rc=$?
+  [ "$grep_rc" -le 1 ] || exit 5
+  # An `if`, not `[ ... ] && printf`: the latter is the loop body's last command, so a final comment
+  # with no verdict would leave the SUBSHELL exiting 1 and the rc check below would report a reader
+  # failure on a perfectly ordinary PR.
+  if [ "$grep_rc" -eq 0 ]; then printf '%s\n' "$found"; fi
 done)
 verdict_rc=$?
 if [ "$verdict_rc" -ne 0 ]; then