#1627 Crash when adding custom field if existing field is selected for editing

[Tony Garnock-Jones]

BibDesk version: Version 1.8.7 (5747)
MacOS version: "System Version: macOS 12.0.1 (21A559)"
Mac hardware:
Model Name: Mac mini
Model Identifier: Macmini9,1
Chip: Apple M1

To reproduce:

1. Open BibDesk
2. Open "Preferences..."
3. Select "Fields"
4. Custom BibTeX Types and Fields --> "Edit..."
5. Select e.g. "electronic" from the "Type" column, though anything will cause the crash
6. Click "+" under the "Required Fields" column (or the "Optional Fields" column)
7. Click "+" again, WITHOUT moving the selection out of the cell containing "New-Field" that was just created.
8. BibDesk will crash.

Variation: Type some unique field name in place of "New-Field", and click "+" again without moving the caret out of the field.

Workaround: Type some unique field name in place of "New-Field", and click OUTSIDE THE FIELD so that the caret disappears; then click "+". A new "New-Field" will appear as expected.

The exception message in the crash report is: "NSTableView data re-entrancy is not supported."

Full crash report text attached.

[Christiaan Hofman]

This will be fixed for the next nightly build.