[RFC PATCH v2 3/4] t7006-pager.sh: more lenient trace checking

[Emily Shaffer <emilyshaffer@google.com>]

A number of tests in t7006-pager.sh are, as a side effect, checking that
'git log' does not invoke any child processes besides the pager. There
is no reason for that guarantee, and it is not explicitly the purpose of
these tests, so let's make the checking more intelligent and flexible.

child_start and child_exit events share a child ID - using that child
ID, we can try to disambiguate which child_exit belongs to which
child_start and limit our validation to only the pager's child process.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 t/t7006-pager.sh | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 0e7cf75435..ac2d91d56b 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -676,7 +676,9 @@ test_expect_success TTY 'git returns SIGPIPE on early pager exit' '
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep pager-used trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:0 " child-exits &&
 	test_path_is_file pager-used
@@ -697,7 +699,9 @@ test_expect_success TTY 'git returns SIGPIPE on early pager non-zero exit' '
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep pager-used trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:1 " child-exits &&
 	test_path_is_file pager-used
@@ -718,7 +722,9 @@ test_expect_success TTY 'git discards pager non-zero exit without SIGPIPE' '
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep pager-used trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:1 " child-exits &&
 	test_path_is_file pager-used
@@ -739,7 +745,9 @@ test_expect_success TTY 'git discards nonexisting pager without SIGPIPE' '
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep does-not-exist trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:127 " child-exits &&
 	test_path_is_file pager-used
@@ -760,7 +768,9 @@ test_expect_success TTY 'git attempts to page to nonexisting pager command, gets
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep does-not-exist trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:-1 " child-exits
 '
@@ -780,7 +790,9 @@ test_expect_success TTY 'git returns SIGPIPE on propagated signals from pager' '
 		test_terminal git log
 	fi &&
 
-	grep child_exit trace.normal >child-exits &&
+	PAGER_CHILD_ID=$(grep pager-used trace.normal | \
+			 sed -n "s/child_start\[\([0-9]\+\)\].*/\1/p") &&
+	grep -F "child_exit["$PAGER_CHILD_ID"]" trace.normal >child-exits &&
 	test_line_count = 1 child-exits &&
 	grep " code:143 " child-exits &&
 	test_path_is_file pager-used
-- 
2.31.1.498.g6c1eba8ee3d-goog