Protect from floating point rounding errors (#302)

CHANGES.rst

@@ -36,6 +36,7 @@ Changed:
 
 Fixed:
 
+* Crash due to floating point rounding error (#302 by Sam Hartman)
 * Setting 'number_format' to *none* caused a crash; now it causes the caption
   label to be omitted.
 * Handle citations and corresponding citation references that are not defined

src/rinoh/layout.py

@@ -257,7 +257,7 @@ def advance(self, height, ignore_overflow=False):
         """Advance the cursor by `height`. If this would cause the cursor to
         point beyond the bottom of the container, an :class:`EndOfContainer`
         exception is raised."""
-        if height <= self.remaining_height:
+        if height <= self.remaining_height + FLOATING_POINT_FUZZ:
             self._self_cursor.grow(height)
         elif ignore_overflow:
             self._self_cursor.grow(float(self.remaining_height))
@@ -271,7 +271,7 @@ def advance2(self, height, ignore_overflow=False):
         bottom of the container.
 
         """
-        if height <= self.remaining_height:
+        if height <= self.remaining_height + FLOATING_POINT_FUZZ:
             self._self_cursor.grow(height)
         elif ignore_overflow:
             self._self_cursor.grow(float(self.remaining_height))
@@ -305,6 +305,9 @@ def log_styleds(index):
             log_styleds(i)
 
 
+FLOATING_POINT_FUZZ = 1e-10
+
+
 class _FlowablesContainer(FlowableTarget, FlowablesContainerBase):
     def __init__(self, name, type, parent, *args, **kwargs):
         super().__init__(parent.document_part, name, type, parent,