Fix indexer error that double counted data in a certain edge case. (#… #1504

Job	Run time
Check Style	40s
Bazel Build (ubuntu-latest, gcc, 9)	25s
CMake Build (ubuntu-latest, gcc, 9)	24s
Documentation Build (1_8_18)	1m 15s
Bazel Build (ubuntu-latest, gcc, 10)	21s
CMake Build (ubuntu-latest, gcc, 10)	42s
Bazel Build (ubuntu-latest, clang, 11)	27s
CMake Build (ubuntu-latest, clang, 11)	42s
CMake Build (windows-latest, msvc)	1m 32s
Python Unit Tests	45s
Upload Documentation	27s
Create Release	0s
	7m 40s

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