Add FloatBarrier before clearpage to prevent figures floating past References

Problem: LaTeX float mechanism pushes figures that don't fit on the current
page to later pages, sometimes past \clearpage into the References section.

Fix:
- _ensure_clearpage_before_bibliography() now injects \FloatBarrier + \clearpage
- FloatBarrier forces all pending figures to render within body pages
- Auto-adds \usepackage{placeins} to preamble if missing
- Injected BEFORE page enforcement, so enforcement sees true page count
  (with all figures placed)

Template: euromlsys/main.tex updated with placeins and FloatBarrier

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JihaoXin

ark/execution.py

@@ -725,24 +725,54 @@ def _enforce_page_count(self, context: str = "post-writing") -> bool:
                 return True
 
     def _ensure_clearpage_before_bibliography(self):
-        """Programmatically ensure \\clearpage appears before \\bibliography in main.tex."""
+        """Ensure \\FloatBarrier + \\clearpage before \\bibliography in main.tex.
+
+        FloatBarrier forces all pending figures to be placed within the body
+        (prevents them from floating past References). clearpage starts a new
+        page for References. Both are injected programmatically.
+        """
         main_tex = self.latex_dir / "main.tex"
         if not main_tex.exists():
             return
         try:
             content = main_tex.read_text()
+            changed = False
+
+            # Ensure \usepackage{placeins} is in preamble (for \FloatBarrier)
+            if r'\usepackage{placeins}' not in content:
+                # Insert after last \usepackage line in preamble
+                import re
+                last_pkg = list(re.finditer(r'\\usepackage(\[.*?\])?\{.*?\}', content))
+                if last_pkg:
+                    insert_pos = last_pkg[-1].end()
+                    content = content[:insert_pos] + '\n\\usepackage{placeins}' + content[insert_pos:]
+                    changed = True
+
             marker = r'\bibliography{'
             if marker not in content:
                 return
-            # Check if \clearpage already precedes \bibliography
-            if '\\clearpage\n' + marker in content or '\\clearpage\n\n' + marker in content:
+
+            # Build the correct pre-bibliography block
+            pre_bib = '\\FloatBarrier\n\\clearpage\n'
+
+            # Check if already correct
+            if pre_bib + marker in content:
+                if changed:
+                    main_tex.write_text(content)
                 return
-            # Insert \clearpage before \bibliography
-            content = content.replace(marker, '\\clearpage\n' + marker)
+
+            # Remove any existing partial insertions and rebuild
+            content = content.replace('\\FloatBarrier\n\\clearpage\n' + marker, marker)
+            content = content.replace('\\FloatBarrier\n' + marker, marker)
+            content = content.replace('\\clearpage\n' + marker, marker)
+            content = content.replace('\\clearpage\n\n' + marker, marker)
+
+            # Insert FloatBarrier + clearpage before bibliography
+            content = content.replace(marker, pre_bib + marker)
             main_tex.write_text(content)
-            self.log("Injected \\clearpage before \\bibliography", "INFO")
+            self.log("Injected \\FloatBarrier + \\clearpage before \\bibliography", "INFO")
         except Exception as e:
-            self.log(f"Failed to inject \\clearpage: {e}", "WARN")
+            self.log(f"Failed to inject FloatBarrier/clearpage: {e}", "WARN")
 
     def _run_writing_phase(self, action_plan: dict, prior_context: str = ""):
         """Execute writing phase for all writing tasks."""

venue_templates/euromlsys/main.tex

@@ -1,10 +1,11 @@
 \documentclass[sigplan,10pt,nonacm,balance=false]{acmart}
 
-% Remove ACM-specific elements for non-ACM venue
 \settopmatter{printacmref=false}
 \renewcommand\footnotetextcopyrightpermission[1]{}
 \pagestyle{plain}
 
+\usepackage{placeins}
+
 \begin{document}
 
 \title{Paper Title}
@@ -31,6 +32,7 @@ \section{Experiments}
 
 \section{Conclusion}
 
+\FloatBarrier
 \clearpage
 \bibliographystyle{ACM-Reference-Format}
 \bibliography{references}