[SPARK-26208] Empty dataframe does not roundtrip for csv with header

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 3.0.0
• Component/s: SQL

Environment

master branch,
commit 034ae305c33b1990b3c1a284044002874c343b4d,
date: Sun Nov 18 16:02:15 2018 +0800

• Assignee: Koert Kuipers
• Reporter: koert kuipers
• Created: 28/Nov/18 18:16
• Updated: 12/Dec/22 18:10
• Resolved: 02/Dec/18 09:39

Description

when we write empty part file for csv and header=true we fail to write header. the result cannot be read back in.

when header=true a part file with zero rows should still have header

Issue Links

• is duplicated by: SPARK-31657 CSV Writer writes no header for empty DataFrames
• relates to: SPARK-15473 CSV fails to write and read back empty dataframe
• links to: [Github] Pull Request #23173 (koertkuipers)