Fix GeoPackage writer silently appending data when target file is in use

[adamnadolny-wizipisi]

Summary

Fixes #1201

When the Overwrite target file if it exists option is enabled but the target .gpkg file cannot be deleted (e.g. it is locked by QGIS or another process on Windows), File.delete() returns False silently. The writer then opens the existing file and appends data instead of overwriting it — resulting in duplicated records with no error reported to the user.

Root cause

In GeopackageInstanceWriter.java (around line 202), the return value of File.delete() was not checked:

java // before fix file.delete(); // silently returns false if file is locked

Fix

Check the return value and throw IOException if deletion fails:

java if (!file.delete()) { throw new IOException("Cannot overwrite existing GeoPackage file (file may be in use): " + file.getAbsolutePath()); }

The exception is caught by the surrounding ry/catch in execute(), which marks the report as failed and records the error — so the user sees a clear error message instead of silently corrupted output.

Test

Added estOverwriteFailsWhenFileInUse() to GeopackageInstanceWriterTest:

• Writes a GeoPackage file
• Simulates "file in use" by holding an open RandomAccessFile handle (mirrors Windows file locking behaviour, e.g. when QGIS has the file open)
• Asserts that the writer reports failure and records an error

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Submitted by: The Wroclaw Institute of Spatial Information and Artificial Intelligence
(WIZIPISI — Wrocławski Instytut Zastosowań Informacji Przestrzennej i Sztucznej Inteligencji)

[stempler]

Thanks a lot for the contribution. Looks good to me so far, now waiting for the workflow runs.
Please make sure to modify the commit message to follow conventional commits (fix: commit)

[github-actions]

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