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Fix sqlcmd hanging for ~10 minutes after query timeout on Linux #682

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Fix sqlcmd hanging for ~10 minutes after query timeout on Linux #682

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11a83d0
Initial plan
Copilot Jan 31, 2026
e227587
Add defer rows.Close() to fix timeout hang on Linux
Copilot Jan 31, 2026
7ca93ed
Merge branch 'main' into copilot/fix-sqlcmd-timeout-issue
dlevy-msft-sql Feb 5, 2026
2245e0d
Add e2e test for query timeout to verify fix
Copilot Feb 5, 2026
5219e2a
Co-authored-by: dlevy-msft-sql <194277063+dlevy-msft-sql@users.norepl…
Copilot Feb 6, 2026
44668cd
Add timing measurement to e2e timeout test to verify quick exit
Copilot Feb 6, 2026
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36 changes: 36 additions & 0 deletions cmd/modern/e2e_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ import (
"strings"
"sync"
"testing"
"time"

"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
Expand Down Expand Up @@ -312,6 +313,41 @@ func TestE2E_PipedInput_WithBytesBuffer_NoPanic(t *testing.T) {
assert.NotContains(t, outputStr, "nil pointer", "should not have nil pointer error")
}

// TestE2E_QueryTimeout_LiveConnection tests that the -t flag properly times out queries
// and doesn't hang for 10 minutes on Linux. This is a regression test for the issue
// where sqlcmd would print "Timeout expired" but then hang for ~10 minutes before exiting.
func TestE2E_QueryTimeout_LiveConnection(t *testing.T) {
skipIfNoLiveConnection(t)
binary := buildBinary(t)

// Use a 1 second timeout with a query that would take 10 seconds
args := append([]string{"-C", "-t", "1", "-Q", "WAITFOR DELAY '00:00:10'"}, getAuthArgs(t)...)
cmd := exec.Command(binary, args...)
cmd.Env = os.Environ()

// Measure execution time - this is the key validation
// The command should complete in a few seconds, not 10 minutes
start := time.Now()
output, err := cmd.CombinedOutput()
elapsed := time.Since(start)
outputStr := string(output)

// The command should fail due to timeout
assert.Error(t, err, "query should timeout and return an error")

// Output should contain timeout message
assert.Contains(t, outputStr, "Timeout expired", "output should contain 'Timeout expired' message")

// Critical: verify the command completed quickly (within 30 seconds, not 10 minutes)
// If the bug exists, this would take ~10 minutes on Linux
maxDuration := 30 * time.Second
if elapsed > maxDuration {
t.Errorf("Command took too long to complete: %v (expected < %v). The timeout hang bug may still exist.", elapsed, maxDuration)
}

t.Logf("Query timed out correctly in %v: %s", elapsed, outputStr)
}

// cleanupBinary removes the temporary build directory containing the test binary.
// TestMain calls this to ensure deterministic cleanup instead of relying on
// eventual OS temp directory maintenance.
Expand Down
3 changes: 3 additions & 0 deletions pkg/sqlcmd/sqlcmd.go
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Original file line number Diff line number Diff line change
Expand Up @@ -431,6 +431,9 @@
}
retmsg := &sqlexp.ReturnMessage{}
rows, qe := s.db.QueryContext(ctx, query, retmsg)
if rows != nil {
defer rows.Close()

Check failure on line 435 in pkg/sqlcmd/sqlcmd.go

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Error return value of `rows.Close` is not checked (errcheck)
}
if qe != nil {
s.Format.AddError(qe)
}
Expand Down
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