Preserve visible Markdown code examples

Authored-By: Codex (GPT-5) <noreply@openai.com>

check.sh

@@ -16,29 +16,72 @@ HEAD="${HEAD_SHA:-}"
 VISIBLE_BODY=$(printf '%s\n' "${BODY}" | awk '
   {
     line=$0
-    while (line != "") {
+    fence_pos=1
+    while (fence_pos <= 4 && substr(line, fence_pos, 1) == " ") fence_pos++
+    fence_char=substr(line, fence_pos, 1)
+    fence_run=0
+    if (fence_char == "`" || fence_char == "~") {
+      while (substr(line, fence_pos + fence_run, 1) == fence_char) fence_run++
+    }
+    if (in_fence) {
+      print line
+      if (fence_char == active_fence_char && fence_run >= active_fence_run) in_fence=0
+      next
+    }
+    if (fence_run >= 3) {
+      in_fence=1
+      active_fence_char=fence_char
+      active_fence_run=fence_run
+      print line
+      next
+    }
+
+    visible=""
+    pos=1
+    while (pos <= length(line)) {
       if (in_comment) {
-        end=index(line, "-->")
-        if (end == 0) {
-          line=""
+        rest=substr(line, pos)
+        comment_end=index(rest, "-->")
+        if (comment_end == 0) {
+          pos=length(line) + 1
           break
         }
-        line=substr(line, end + 3)
+        visible=visible " "
+        pos += comment_end + 2
         in_comment=0
+        continue
       }
-      start=index(line, "<!--")
-      if (start == 0) break
-      before=substr(line, 1, start - 1)
-      rest=substr(line, start + 4)
-      end=index(rest, "-->")
-      if (end == 0) {
-        line=before
+
+      if (substr(line, pos, 1) == "`") {
+        ticks=1
+        while (substr(line, pos + ticks, 1) == "`") ticks++
+        close_pos=pos + ticks
+        found_close=0
+        while (close_pos <= length(line)) {
+          if (substr(line, close_pos, ticks) == substr(line, pos, ticks) &&
+              substr(line, close_pos + ticks, 1) != "`") {
+            found_close=1
+            break
+          }
+          close_pos++
+        }
+        if (found_close) {
+          visible=visible substr(line, pos, close_pos + ticks - pos)
+          pos=close_pos + ticks
+          continue
+        }
+      }
+
+      if (substr(line, pos, 4) == "<!--") {
+        visible=visible " "
         in_comment=1
-        break
+        pos += 4
+        continue
       }
-      line=before substr(rest, end + 3)
+      visible=visible substr(line, pos, 1)
+      pos++
     }
-    print line
+    print visible
   }
 ')