Mask edges when doBrighterFatter=True.

The edges of amplifiers that have had the brighter-fatter correction
applied may not have had the appropriate correction applied.  To
reflect this fact, ensure that the number of edge pixels matching the
convolution boundary (1/2 the kernel size) are masked with the EDGE
bit, using the maskEdges method.

Docstring clarification.

python/lsst/ip/isr/isrTask.py

@@ -1325,6 +1325,16 @@ def run(self, ccdExposure, camera=None, bias=None, linearizer=None, crosstalkSou
             bfCorr -= interpExp.getMaskedImage().getImage()
             image += bfCorr
 
+            # Applying the brighter-fatter correction applies a
+            # convolution to the science image. At the edges this
+            # convolution may not have sufficient valid pixels to
+            # produce a valid correction. Mark pixels within the size
+            # of the brighter-fatter kernel as EDGE to warn of this
+            # fact.
+            self.maskEdges(ccdExposure, numEdgePixels=numpy.max(bfKernel.shape) // 2,
+                           maskPlane="EDGE")
+            self.log.warn("Ensuring image edges are masked as SUSPECT to the brighter-fatter kernel size.")
+
             self.debugView(ccdExposure, "doBrighterFatter")
 
         if self.config.doDark:
@@ -2070,7 +2080,7 @@ def maskDefect(self, exposure, defectBaseList):
             Exposure to process.
         defectBaseList : `lsst.meas.algorithms.Defects` or `list` of
                          `lsst.afw.image.DefectBase`.
-            List of defects to mask and interpolate.
+            List of defects to mask.
 
         Notes
         -----
@@ -2117,8 +2127,13 @@ def maskAndInterpolateDefects(self, exposure, defectBaseList):
         ----------
         exposure : `lsst.afw.image.Exposure`
             Exposure to process.
-        defectBaseList : `List` of `Defects`
+        defectBaseList : `lsst.meas.algorithms.Defects` or `list` of
+                         `lsst.afw.image.DefectBase`.
+            List of defects to mask and interpolate.
 
+        See Also
+        --------
+        lsst.ip.isr.isrTask.maskDefect()
         """
         self.maskDefect(exposure, defectBaseList)
         self.maskEdges(exposure, numEdgePixels=self.config.numEdgeSuspect,