Modified tex2pdf to fail without hanging

This can happen when files are missing. pdflatex asks for files via stdin, but
tex2pdf is capturing stdout to make up for pdflatex not providing a valid
integer returncode to indicate failure.

publisher/build_paper.py

@@ -4,6 +4,7 @@
 import os.path
 import sys
 import re
+import tempfile
 import glob
 import shutil
 
@@ -88,17 +89,33 @@ def tex2pdf(out_path):
     command_line = 'cd %s ' % out_path + \
                    ' ; pdflatex -halt-on-error paper.tex'
 
-    run = subprocess.Popen(command_line, shell=True, stdout=subprocess.PIPE)
+    # -- dummy tempfile is a hacky way to prevent pdflatex
+    #    from asking for any missing files via stdin prompts,
+    #    which mess up our build process.
+    dummy = tempfile.TemporaryFile()
+    run = subprocess.Popen(command_line, shell=True,
+            stdin=dummy,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE)
     out, err = run.communicate()
 
-    run = subprocess.Popen(command_line, shell=True, stdout=subprocess.PIPE)
-    out, err = run.communicate()
+    # -- returncode always 0, have to check output for error
+    if "Fatal" not in out:
+        # -- pdflatex has to run twice to actually work
+        run = subprocess.Popen(command_line, shell=True,
+                stdin=dummy,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE)
+        out, err = run.communicate()
 
-    if "Fatal" in out:
+    if "Fatal" in out or run.returncode:
         print "PDFLaTeX error output:"
         print "=" * 80
         print out
         print "=" * 80
+        if err:
+            print err
+            print "=" * 80
 
     return out