[PATCH] t4215: don't put git commands upstream of pipe

[Denton Liu <liu.denton@gmail.com>]

When git commands are placed in the upstream of a pipe, their return
codes are lost. In this particular case, it is especially bad since we
are testing the intricacies of `git log --graph` behavior and if we hit
an unexpected failure or segfault, we want to know this.

Redirect the output of git commands upstream of pipe into a file and
have sed read from that file so that git failures are detected.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
Thanks for the suggestion, Gábor. (Is that how I should refer to you? I
recently learned that some poeple write their names in ALL CAPS as a
convention.)

A little late to the party but since this cleanup hasn't been done yet,
let's do it now. We can apply this patch to the tip of
'jc/log-graph-simplify'.

 t/t4215-log-skewed-merges.sh | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/t/t4215-log-skewed-merges.sh b/t/t4215-log-skewed-merges.sh
index d33c6438d8..0a2555fb28 100755
--- a/t/t4215-log-skewed-merges.sh
+++ b/t/t4215-log-skewed-merges.sh
@@ -31,7 +31,8 @@ test_expect_success 'log --graph with merge fusing with its left and right neigh
 	git checkout _p && git merge --no-ff _r -m G &&
 	git checkout @^^ && git merge --no-ff _p -m H &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -68,7 +69,8 @@ test_expect_success 'log --graph with left-skewed merge' '
 	git checkout 0_p && git merge --no-ff 0_s -m 0_G &&
 	git checkout @^ && git merge --no-ff 0_q 0_r 0_t 0_p -m 0_H &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -99,7 +101,8 @@ test_expect_success 'log --graph with nested left-skewed merge' '
 	git checkout 1_p && git merge --no-ff 1_r -m 1_G &&
 	git checkout @^^ && git merge --no-ff 1_p -m 1_H &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -139,7 +142,8 @@ test_expect_success 'log --graph with nested left-skewed merge following normal
 	git checkout -b 2_s @^^ && git merge --no-ff 2_q -m 2_J &&
 	git checkout 2_p && git merge --no-ff 2_s -m 2_K &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -175,7 +179,8 @@ test_expect_success 'log --graph with nested right-skewed merge following left-s
 	git checkout 3_p && git merge --no-ff 3_r -m 3_H &&
 	git checkout @^^ && git merge --no-ff 3_p -m 3_J &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -210,7 +215,8 @@ test_expect_success 'log --graph with right-skewed merge following a left-skewed
 	git merge --no-ff 4_p -m 4_G &&
 	git checkout @^^ && git merge --no-ff 4_s -m 4_H &&
 
-	git log --graph --date-order --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --date-order --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
@@ -250,7 +256,8 @@ test_expect_success 'log --graph with octopus merge with column joining its penu
 	git checkout 5_r &&
 	git merge --no-ff 5_s -m 5_H &&
 
-	git log --graph --pretty=tformat:%s | sed "s/ *$//" >actual &&
+	git log --graph --pretty=tformat:%s >actual.raw &&
+	sed "s/ *$//" actual.raw >actual &&
 	test_cmp expect actual
 '
 
-- 
2.24.0.300.g722ba42680