I am trying to perform a vector clip analysis (vector-->geoprocessing tools pull-down menu) using two complicated vector layers and am getting erroneous results. The clip 'Input layer' is shown here:
and the 'Clip layer' is shown here:
Both layers are in the same projection (EPSG 2229) and neither layer has any features selected. However, the analysis result (below) is incomplete, it ignores the two input layer features furthest to the west (blue and purple). The result would be expected if I had all but the two furthest west input features selected, but this is not the case. Furthermore, I have performed the same analysis in different work sessions (and even the prior QGIS version 2.18.13) and gotten different results, but always with at least one of the input features being ignored (either wholly or partially).
I have been able to perform complicated clip analyses in QGIS many times in the past. Sometimes it would take a while, but I could count on valid results. I think this problem first started presenting itself within the last couple of months... I'm not sure what changed. Has anybody else had this problem? Any suggestions?