check_strvec_loc() checks each the strvec item by looping through them
and comparing them with expected values.  If a check fails then we'd
like to know which item is affected.  It reports that information by
building a strbuf and delivering its contents using a failing assertion.

Here's an example in which there are less items in the strvec than
expected; the index of the missing item is reported in the last line:

   # check "vec->nr > nr" failed at t/unit-tests/t-strvec.c:19
   #    left: 1
   #   right: 1
   # check "strvec index 1" failed at t/unit-tests/t-strvec.c:71

Note that it is also reported in the third line, i.e. the variable
"nr" contains that index.

Stop printing the index explicitly for checks that already report it.
The message for the same condition as above becomes:

   # check "vec->nr > nr" failed at t/unit-tests/t-strvec.c:19
   #    left: 1
   #   right: 1

For the string comparison, whose error message doesn't include the
index, report it using the simpler and more appropriate test_msg()
instead.  Report the index using its actual name and format the line
like the preceding ones.  The message for an unexpected string value
becomes:

   # check "!strcmp(vec->v[nr], str)" failed at t/unit-tests/t-strvec.c:24
   #    left: "foo"
   #   right: "bar"
   #      nr: 0

Reported-by: Phillip Wood <redacted>
---
 t/unit-tests/t-strvec.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/t/unit-tests/t-strvec.c b/t/unit-tests/t-strvec.c
index d4615ab06d..236203af61 100644
--- a/t/unit-tests/t-strvec.c
+++ b/t/unit-tests/t-strvec.c

@@ -17,12 +17,12 @@ static void check_strvec_loc(const char *loc, struct strvec *vec, ...)
 			break;

 		if (!check_uint(vec->nr, >, nr) ||
-		    !check_uint(vec->alloc, >, nr) ||
-		    !check_str(vec->v[nr], str)) {
-			struct strbuf msg = STRBUF_INIT;
-			strbuf_addf(&msg, "strvec index %"PRIuMAX, (uintmax_t) nr);
-			test_assert(loc, msg.buf, 0);
-			strbuf_release(&msg);
+		    !check_uint(vec->alloc, >, nr)) {
+			va_end(ap);
+			return;
+		}
+		if (!check_str(vec->v[nr], str)) {
+			test_msg("     nr: %"PRIuMAX, (uintmax_t)nr);
 			va_end(ap);
 			return;
 		}
--

2.45.2