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author | Rob Pike <r@golang.org> | 2019-11-11 10:55:32 +1100 |
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committer | Rob Pike <r@golang.org> | 2019-11-12 05:06:42 +0000 |
commit | b8cb75fb17511538524ac304abe68e62699c4e23 (patch) | |
tree | a43e7984bd5161b860f0c409069fdc3c1e890573 /src/text | |
parent | b60c7a5c7f50fc75ddecb7f1dea6c2e47a12b42c (diff) | |
download | go-b8cb75fb17511538524ac304abe68e62699c4e23.tar.gz go-b8cb75fb17511538524ac304abe68e62699c4e23.zip |
text/template: add error check for parenthesized first argument in pipeline
An error check was missing: If the first argument of a pipeline is
parenthesized, and the pipeline has further arguments, then
syntactically the pipeline is a function invocation and there must
be a "call". Tricky rare corner case, but easily caught.
Add the error check and some tests to verify behavior.
Fixes #31810.
Change-Id: Ica80b7c11284e4ea9e8cc94a01dbbc9a67e42079
Reviewed-on: https://go-review.googlesource.com/c/go/+/206124
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/text')
-rw-r--r-- | src/text/template/exec.go | 3 | ||||
-rw-r--r-- | src/text/template/exec_test.go | 44 |
2 files changed, 46 insertions, 1 deletions
diff --git a/src/text/template/exec.go b/src/text/template/exec.go index f9bc5d980c..ac3e741390 100644 --- a/src/text/template/exec.go +++ b/src/text/template/exec.go @@ -461,7 +461,8 @@ func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final ref // Must be a function. return s.evalFunction(dot, n, cmd, cmd.Args, final) case *parse.PipeNode: - // Parenthesized pipeline. The arguments are all inside the pipeline; final is ignored. + // Parenthesized pipeline. The arguments are all inside the pipeline; final must be absent. + s.notAFunction(cmd.Args, final) return s.evalPipeline(dot, n) case *parse.VariableNode: return s.evalVariableNode(dot, n, cmd.Args, final) diff --git a/src/text/template/exec_test.go b/src/text/template/exec_test.go index f24a59e549..2b299b0bf6 100644 --- a/src/text/template/exec_test.go +++ b/src/text/template/exec_test.go @@ -352,6 +352,12 @@ var execTests = []execTest{ {"field on interface", "{{.foo}}", "<no value>", nil, true}, {"field on parenthesized interface", "{{(.).foo}}", "<no value>", nil, true}, + // Issue 31810: Parenthesized first element of pipeline with arguments. + // See also TestIssue31810. + {"unparenthesized non-function", "{{1 2}}", "", nil, false}, + {"parenthesized non-function", "{{(1) 2}}", "", nil, false}, + {"parenthesized non-function with no args", "{{(1)}}", "1", nil, true}, // This is fine. + // Method calls. {".Method0", "-{{.Method0}}-", "-M0-", tVal, true}, {".Method1(1234)", "-{{.Method1 1234}}-", "-1234-", tVal, true}, @@ -1648,3 +1654,41 @@ func TestExecutePanicDuringCall(t *testing.T) { } } } + +// Issue 31810. Check that a parenthesized first argument behaves properly. +func TestIssue31810(t *testing.T) { + // A simple value with no arguments is fine. + var b bytes.Buffer + const text = "{{ (.) }}" + tmpl, err := New("").Parse(text) + if err != nil { + t.Error(err) + } + err = tmpl.Execute(&b, "result") + if err != nil { + t.Error(err) + } + if b.String() != "result" { + t.Errorf("%s got %q, expected %q", text, b.String(), "result") + } + + // Even a plain function fails - need to use call. + f := func() string { return "result" } + b.Reset() + err = tmpl.Execute(&b, f) + if err == nil { + t.Error("expected error with no call, got none") + } + + // Works if the function is explicitly called. + const textCall = "{{ (call .) }}" + tmpl, err = New("").Parse(textCall) + b.Reset() + err = tmpl.Execute(&b, f) + if err != nil { + t.Error(err) + } + if b.String() != "result" { + t.Errorf("%s got %q, expected %q", textCall, b.String(), "result") + } +} |