Array merge example SIGSEGV

[splitice]

Tried the array merge example from this repository, it immediately crashed.

$ yq ea '((.[] | {.name: .}) as $item ireduce ({}; . * $item )) as $uniqueMap  | ( $uniqueMap  | to_entries | .[]) as $item ireduce([]; . + $item.value)' 1.yaml 2.yaml
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x672c14]

goroutine 1 [running]:
container/list.(*List).Len(...)
        /opt/hostedtoolcache/go/1.17.6/x64/src/container/list/list.go:66
github.com/mikefarah/yq/v4/pkg/yqlib.reduceOperator(0xc0000897d0, {0xc000302fc0, 0x0, 0x2}, 0xc00027ae10)
        /home/runner/work/yq/yq/pkg/yqlib/operator_reduce.go:27 +0x114
github.com/mikefarah/yq/v4/pkg/yqlib.(*dataTreeNavigator).GetMatchingNodes(0x0, {0xc000302fc0, 0x0, 0x80}, 0xc00027ae10)
        /home/runner/work/yq/yq/pkg/yqlib/data_tree_navigator.go:37 +0x1c3
github.com/mikefarah/yq/v4/pkg/yqlib.assignVariableOperator(0xc0000897d0, {0xc0001cbfb0, 0x0, 0x0}, 0xc00027ae40)
        /home/runner/work/yq/yq/pkg/yqlib/operator_variables.go:23 +0xbc
github.com/mikefarah/yq/v4/pkg/yqlib.(*dataTreeNavigator).GetMatchingNodes(0x763d22, {0xc0001cbfb0, 0x0, 0x10}, 0xc00027ae40)
        /home/runner/work/yq/yq/pkg/yqlib/data_tree_navigator.go:37 +0x1c3
github.com/mikefarah/yq/v4/pkg/yqlib.pipeOperator(0xc0000897d0, {0xc0001cbfb0, 0x0, 0x0}, 0xc00027b020)
        /home/runner/work/yq/yq/pkg/yqlib/operator_pipe.go:9 +0x3d
github.com/mikefarah/yq/v4/pkg/yqlib.(*dataTreeNavigator).GetMatchingNodes(0xc0002cf280, {0xc0001cbfb0, 0x0, 0xa0}, 0xc00027b020)
        /home/runner/work/yq/yq/pkg/yqlib/data_tree_navigator.go:37 +0x1c3
github.com/mikefarah/yq/v4/pkg/yqlib.(*allAtOnceEvaluator).EvaluateCandidateNodes(0xc0002dbcb8, {0x7fffd87da345, 0x7fffd87da3dc}, 0x8)
        /home/runner/work/yq/yq/pkg/yqlib/all_at_once_evaluator.go:41 +0x67
github.com/mikefarah/yq/v4/pkg/yqlib.(*allAtOnceEvaluator).EvaluateFiles(0xc00000e018, {0x7fffd87da345, 0x8f}, {0xc000089c90, 0x2, 0xc000014f5c}, {0x7ebe18, 0xc0002ccf00}, 0x1, {0x7eb3b0, ...})
        /home/runner/work/yq/yq/pkg/yqlib/all_at_once_evaluator.go:84 +0x35d
github.com/mikefarah/yq/v4/cmd.evaluateAll(0xc0000a5680, {0xc000089c80, 0x3, 0x3})
        /home/runner/work/yq/yq/cmd/evaluate_all_command.go:147 +0x156e
github.com/spf13/cobra.(*Command).execute(0xc0000a5680, {0xc000089c50, 0x3, 0x3})
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:856 +0x60e
github.com/spf13/cobra.(*Command).ExecuteC(0xc0000a5180)
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:974 +0x3bc
github.com/spf13/cobra.(*Command).Execute(...)
        /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.3.0/command.go:902
main.main()
        /home/runner/work/yq/yq/yq.go:22 +0x190

$ yq --version
yq (https://github.com/mikefarah/yq/) version 4.19.1

Inputs:

1.yaml

abc:
 - a: 1
   c: 4
 - a: 2

2.yaml

abc:
 - a: 2
   b: 3
 - a: 2

[mikefarah]

The SIGV is definitely a bug, thanks for reporting. I've put a fix in for the next release.

That merge-by-array-key.sh was a temporary file I had accidentally checked in while working out a generic way to do just that. I've removed it from the rep (sorry for the confusion!)

Have a look at https://mikefarah.gitbook.io/yq/operators/multiply-merge#merge-arrays-of-objects-together-matching-on-a-key for the actual generic solution

[mikefarah]

SIGV fixed in 4.20.1