From 92b948654584611d22af72e72d4c1604d4f3f0a2 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 15 Apr 2016 21:40:27 +0530
Subject: [PATCH] PDF Output: Make fix for blank page at end of section also
 work when headers/footers are specified

---
 src/calibre/ebooks/pdf/render/engine.py    | 22 ++++++++++++++++++----
 src/calibre/ebooks/pdf/render/from_html.py |  2 +-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/calibre/ebooks/pdf/render/engine.py b/src/calibre/ebooks/pdf/render/engine.py
index cb4a910808..c0700cbcfc 100644
--- a/src/calibre/ebooks/pdf/render/engine.py
+++ b/src/calibre/ebooks/pdf/render/engine.py
@@ -59,7 +59,7 @@ class PdfEngine(QPaintEngine):
     def __init__(self, file_object, page_width, page_height, left_margin,
                  top_margin, right_margin, bottom_margin, width, height,
                  errors=print, debug=print, compress=True,
-                 mark_links=False):
+                 mark_links=False, opts=None):
         QPaintEngine.__init__(self, self.FEATURES)
         self.file_object = file_object
         self.compress, self.mark_links = compress, mark_links
@@ -89,6 +89,10 @@ class PdfEngine(QPaintEngine):
         self.current_page_inited = False
         self.content_written_to_current_page = False
         self.qt_hack, err = plugins['qt_hack']
+        self.has_footers = opts is not None and (opts.pdf_page_numbers or opts.pdf_footer_template is not None)
+        self.has_headers = opts is not None and opts.pdf_header_template is not None
+        self.header_height = (opts.margin_top or 0) if opts else 0
+        self.footer_height = (opts.margin_bottom) or 0 if opts else 0
         if err:
             raise RuntimeError('Failed to load qt_hack with err: %s'%err)
 
@@ -251,7 +255,6 @@ class PdfEngine(QPaintEngine):
 
     @store_error
     def drawTextItem(self, point, text_item):
-        self.content_written_to_current_page = 'drawTextItem'
         # return super(PdfEngine, self).drawTextItem(point, text_item)
         self.apply_graphics_state()
         gi = GlyphInfo(*self.qt_hack.get_glyphs(point, text_item))
@@ -281,6 +284,17 @@ class PdfEngine(QPaintEngine):
             glyphs.append((x-last_x, last_y - y, glyph_index))
             last_x, last_y = x, y
 
+        if not self.content_written_to_current_page:
+            ypositions = [y for x, y in gi.positions]
+            miny = min(ypositions or (0,))
+            maxy = max(ypositions or (self.pixel_height,))
+            page_top = self.header_height if self.has_headers else 0
+            page_bottom = self.pixel_height - (self.footer_height if self.has_footers else 0)
+            if page_top <= miny <= page_bottom or page_top <= maxy <= page_bottom:
+                self.content_written_to_current_page = 'drawTextItem'
+            else:
+                self.debug('Text in header/footer: miny=%s maxy=%s page_top=%s page_bottom=%s'% (
+                    miny, maxy, page_top, page_bottom))
         self.pdf.draw_glyph_run([gi.stretch, 0, 0, -1, 0, 0], gi.size, metrics,
                                 glyphs)
 
@@ -326,7 +340,7 @@ class PdfDevice(QPaintDevice):  # {{{
     def __init__(self, file_object, page_size=A4, left_margin=inch,
                  top_margin=inch, right_margin=inch, bottom_margin=inch,
                  xdpi=1200, ydpi=1200, errors=print, debug=print,
-                 compress=True, mark_links=False):
+                 compress=True, mark_links=False, opts=None):
         QPaintDevice.__init__(self)
         self.xdpi, self.ydpi = xdpi, ydpi
         self.page_width, self.page_height = page_size
@@ -338,7 +352,7 @@ class PdfDevice(QPaintDevice):  # {{{
                                 left_margin, top_margin, right_margin,
                                 bottom_margin, self.width(), self.height(),
                                 errors=errors, debug=debug, compress=compress,
-                                mark_links=mark_links)
+                                mark_links=mark_links, opts=opts)
         self.add_outline = self.engine.add_outline
         self.add_links = self.engine.add_links
 
diff --git a/src/calibre/ebooks/pdf/render/from_html.py b/src/calibre/ebooks/pdf/render/from_html.py
index c87061b286..5cc54aff1d 100644
--- a/src/calibre/ebooks/pdf/render/from_html.py
+++ b/src/calibre/ebooks/pdf/render/from_html.py
@@ -182,7 +182,7 @@ class PDFWriter(QObject):
                              top_margin=0, right_margin=mr, bottom_margin=0,
                              xdpi=xdpi, ydpi=ydpi, errors=self.log.error,
                              debug=self.log.debug, compress=not
-                             opts.uncompressed_pdf,
+                             opts.uncompressed_pdf, opts=opts,
                              mark_links=opts.pdf_mark_links)
         self.footer = opts.pdf_footer_template
         if self.footer: