From a20cb4ca5c14ff27bdf16989d450c83b22f156d8 Mon Sep 17 00:00:00 2001 From: Tim Möhlmann Date: Thu, 13 Aug 2020 11:56:31 +0300 Subject: database/sql: make Rows.Scan properly wrap underlying errors The prior implementation used the format verb %v which unfortunately improperly wrapped any underlying scanner errors, and we couldn't use errors.Is nor errors.As. This change fixes that by using the %w verb. Added a unit to ensure that both error sub string matching works, but also that errors.Is works as expected. Fixes #38099 Change-Id: Iea667041dd8081d961246f77f2542330417292dc Reviewed-on: https://go-review.googlesource.com/c/go/+/248337 Reviewed-by: Emmanuel Odeke Reviewed-by: Daniel Theophanes Run-TryBot: Emmanuel Odeke TryBot-Result: Gobot Gobot --- src/database/sql/sql.go | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'src/database/sql/sql.go') diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go index b3d0653f5c..0b85db66b9 100644 --- a/src/database/sql/sql.go +++ b/src/database/sql/sql.go @@ -3110,6 +3110,9 @@ func rowsColumnInfoSetupConnLocked(rowsi driver.Rows) []*ColumnType { // "select cursor(select * from my_table) from dual", into a // *Rows value that can itself be scanned from. The parent // select query will close any cursor *Rows if the parent *Rows is closed. +// +// If any of the first arguments implementing Scanner returns an error, +// that error will be wrapped in the returned error func (rs *Rows) Scan(dest ...interface{}) error { rs.closemu.RLock() @@ -3133,7 +3136,7 @@ func (rs *Rows) Scan(dest ...interface{}) error { for i, sv := range rs.lastcols { err := convertAssignRows(dest[i], sv, rs) if err != nil { - return fmt.Errorf(`sql: Scan error on column index %d, name %q: %v`, i, rs.rowsi.Columns()[i], err) + return fmt.Errorf(`sql: Scan error on column index %d, name %q: %w`, i, rs.rowsi.Columns()[i], err) } } return nil -- cgit v1.3