ghostscript, qpdf: Restore API backward compatibility

ocrmypdf/exec/ghostscript.py

@@ -86,8 +86,8 @@ def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
             raise SubprocessOutputError()
 
 
-def generate_pdfa(*, pdf_version, pdf_pages, output_file, compression, log,
-                  threads=1):
+def generate_pdfa(pdf_pages, output_file, compression, log,
+                  threads=1, pdf_version='1.5'):
     compression_args = []
     if compression == 'jpeg':
         compression_args = [
@@ -115,8 +115,8 @@ def generate_pdfa(*, pdf_version, pdf_pages, output_file, compression, log,
             "-dQUIET",
             "-dBATCH",
             "-dNOPAUSE",
-            '-dCompatibilityLevel=' + str(pdf_version),
-            '-dNumRenderingThreads=' + str(threads),
+            "-dCompatibilityLevel=" + str(pdf_version),
+            "-dNumRenderingThreads=" + str(threads),
             "-sDEVICE=pdfwrite",
             "-dAutoRotatePages=/None",
             "-sColorConversionStrategy=/RGB",

ocrmypdf/exec/qpdf.py

@@ -120,13 +120,17 @@ def split_pages(input_file, work_folder, npages):
         run(args_qpdf, check=True)
 
 
-def merge(*, min_version, input_files, output_file):
+def merge(input_files, output_file, min_version=None):
     """Merge the list of input files (all filenames) into the output file.
 
     The input files may contain one or more pages.
     """
+    version_arg = ['--min-version={}'.format(min_version)] \
+                  if min_version else []
+
     args_qpdf = [
-        get_program('qpdf'), '--min-version={}'.format(min_version),
+        get_program('qpdf')
+    ] + version_arg + [
         input_files[0], '--pages'
     ] + input_files + ['--', output_file]
     run(args_qpdf, check=True)