diff --git a/tests/data/Makefile.am b/tests/data/Makefile.am
index 9311558e13..a47680d6dd 100644
--- a/tests/data/Makefile.am
+++ b/tests/data/Makefile.am
@@ -284,6 +284,7 @@ test3100 test3101 test3102 test3103 test3104 test3105 test3106 \
test3200 test3201 test3202 test3203 test3204 test3205 test3206 test3207 \
test3208 test3209 test3210 test3211 test3212 test3213 test3214 test3215 \
test3216 test3217 test3218 test3219 test3220 test3221 test3222 \
+test3223 test3224 test3225 test3226 \
\
test3300 test3301 test3302 test3303 test3304 test3305 \
\
diff --git a/tests/data/test3223 b/tests/data/test3223
new file mode 100644
index 0000000000..5748d6d07a
--- /dev/null
+++ b/tests/data/test3223
@@ -0,0 +1,67 @@
+
+
+# A partial/aborted HTTP/1.1 response marks the transfer premature.
+# multi_conn_should_close() then closes non-multiplexed connections so they
+# cannot be reused by a later transfer in the same process.
+
+
+HTTP
+HTTP GET
+CURLE_PARTIAL_FILE
+connection reuse
+--next
+
+
+
+
+HTTP/1.1 200 OK swsclose
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 100
+Content-Type: text/plain
+
+0123456789
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+OK
+
+
+connection-monitor
+
+
+
+
+http
+
+
+HTTP connection not reused after partial/aborted response
+
+
+http://%HOSTIP:%HTTPPORT/%TESTNUMBER -o %LOGDIR/3223-1 -w "connects=%{num_connects}/" --next http://%HOSTIP:%HTTPPORT/%TESTNUMBER0001 -o %LOGDIR/3223-2 -w "connects=%{num_connects}/"
+
+
+
+
+GET /%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+[DISCONNECT]
+GET /%TESTNUMBER0001 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+[DISCONNECT]
+
+# Second transfer must open a new connection (cannot reuse after premature).
+
+connects=1/connects=1/
+
+
+
diff --git a/tests/data/test3224 b/tests/data/test3224
new file mode 100644
index 0000000000..4e62303aeb
--- /dev/null
+++ b/tests/data/test3224
@@ -0,0 +1,69 @@
+
+
+# HTTP has PROTOPT_CREDSPERREQUEST: Basic credentials are attached to the
+# request, not to the connection for reuse matching. Different -u values
+# therefore still reuse the idle connection (see also test1134). Protocols
+# without CREDSPERREQUEST (and NTLM/Negotiate mid-handshake) refuse reuse.
+# This test pins the HTTP Basic behavior with an explicit num_connects check.
+
+
+HTTP
+HTTP GET
+HTTP Basic auth
+connection reuse
+--next
+
+
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+A1
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+B2
+
+
+connection-monitor
+
+
+
+
+http
+
+
+HTTP connection reused across different Basic auth credentials
+
+
+http://%HOSTIP:%HTTPPORT/%TESTNUMBER -u user1:password1 -o %LOGDIR/3224-1 -w "connects=%{num_connects}/" --next http://%HOSTIP:%HTTPPORT/%TESTNUMBER0001 -u user2:password2 -o %LOGDIR/3224-2 -w "connects=%{num_connects}/"
+
+
+
+
+GET /%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Authorization: Basic %b64[user1:password1]b64%
+User-Agent: curl/%VERSION
+Accept: */*
+
+GET /%TESTNUMBER0001 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+Authorization: Basic %b64[user2:password2]b64%
+User-Agent: curl/%VERSION
+Accept: */*
+
+[DISCONNECT]
+
+
+connects=1/connects=0/
+
+
+
diff --git a/tests/data/test3225 b/tests/data/test3225
new file mode 100644
index 0000000000..a853f40fc8
--- /dev/null
+++ b/tests/data/test3225
@@ -0,0 +1,69 @@
+
+
+# url_match_destination() / Curl_peer_same_destination() require matching
+# origin hostname and port. Different Host names that resolve to the same
+# address must not share a connection. Both connections may stay in the
+# pool until process exit, so the server may see two DISCONNECT events only
+# at the end; num_connects proves a new connection was opened.
+
+
+HTTP
+HTTP GET
+--resolve
+connection reuse
+--next
+
+
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+H1
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+H2
+
+
+connection-monitor
+
+
+
+
+http
+
+
+HTTP connection not reused when target host changes
+
+
+http://host-a.example.test:%HTTPPORT/%TESTNUMBER --resolve host-a.example.test:%HTTPPORT:%HOSTIP -o %LOGDIR/3225-1 -w "connects=%{num_connects}/" --next http://host-b.example.test:%HTTPPORT/%TESTNUMBER0001 --resolve host-b.example.test:%HTTPPORT:%HOSTIP -o %LOGDIR/3225-2 -w "connects=%{num_connects}/"
+
+
+
+
+GET /%TESTNUMBER HTTP/1.1
+Host: host-a.example.test:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+GET /%TESTNUMBER0001 HTTP/1.1
+Host: host-b.example.test:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+[DISCONNECT]
+[DISCONNECT]
+
+# Same IP via --resolve, different Host names => new connection each time.
+
+connects=1/connects=1/
+
+
+
diff --git a/tests/data/test3226 b/tests/data/test3226
new file mode 100644
index 0000000000..92fa2421ef
--- /dev/null
+++ b/tests/data/test3226
@@ -0,0 +1,63 @@
+
+
+# Positive control: same host reuses the idle connection
+# (second transfer reports num_connects=0).
+
+
+HTTP
+HTTP GET
+connection reuse
+--next
+
+
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+OK
+
+
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Content-Length: 3
+Content-Type: text/plain
+
+OK
+
+
+connection-monitor
+
+
+
+
+http
+
+
+HTTP connection is reused for same host
+
+
+http://%HOSTIP:%HTTPPORT/%TESTNUMBER -o %LOGDIR/3226-1 -w "connects=%{num_connects}/" --next http://%HOSTIP:%HTTPPORT/%TESTNUMBER0001 -o %LOGDIR/3226-2 -w "connects=%{num_connects}/"
+
+
+
+
+GET /%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+GET /%TESTNUMBER0001 HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+[DISCONNECT]
+
+
+connects=1/connects=0/
+
+
+
diff --git a/tests/http/test_12_reuse.py b/tests/http/test_12_reuse.py
index 8ff062d6dc..d4e2f70861 100644
--- a/tests/http/test_12_reuse.py
+++ b/tests/http/test_12_reuse.py
@@ -71,3 +71,71 @@ class TestReuse:
r.check_response(count=count, http_status=200)
# Connections time out on server before we send another request,
assert r.total_connects == count
+
+ # After a partial/aborted HTTP/1.1 response the connection must not be
+ # reused (multi_conn_should_close with premature on non-multiplexed conn).
+ @pytest.mark.parametrize("proto", ['http/1.1'])
+ def test_12_03_no_reuse_after_partial(self, env: Env, httpd, nghttpx, proto):
+ curl = CurlClient(env=env)
+ auth = env.authority_for(env.domain1, proto)
+ # Server promises more bytes than it sends, then resets.
+ partial = f'https://{auth}/curltest/tweak?id=0&chunks=1&chunk_size=100&body_error=reset'
+ ok = f'https://{auth}/data.json'
+ r = curl.http_download(urls=[partial, ok], alpn_proto=proto, extra_args=[
+ '--retry', '0',
+ ])
+ # First transfer fails (partial/reset); second succeeds on a new connection.
+ assert len(r.stats) == 2, r.dump_logs()
+ assert r.stats[0]['exitcode'] != 0, r.dump_logs()
+ assert r.stats[1].get('http_code') == 200, r.dump_logs()
+ # Both transfers must open their own connection.
+ assert r.stats[0]['num_connects'] == 1, r.dump_logs()
+ assert r.stats[1]['num_connects'] == 1, r.dump_logs()
+ assert r.total_connects == 2, r.dump_logs()
+
+ # HTTP uses PROTOPT_CREDSPERREQUEST: Basic credentials are per request, so
+ # different -u values still reuse the idle connection (unlike NTLM/Negotiate
+ # which bind credentials onto the connection).
+ @pytest.mark.parametrize("proto", ['http/1.1'])
+ def test_12_04_reuse_different_basic_credentials(self, env: Env, httpd, nghttpx, proto):
+ curl = CurlClient(env=env)
+ url1 = f'https://{env.authority_for(env.domain1, proto)}/data.json?cred=1'
+ url2 = f'https://{env.authority_for(env.domain1, proto)}/data.json?cred=2'
+ r = curl.http_download(urls=[url1, url2], alpn_proto=proto, url_options={
+ url1: ['-u', 'user1:password1'],
+ url2: ['-u', 'user2:password2'],
+ })
+ assert len(r.stats) == 2, r.dump_logs()
+ assert r.stats[0].get('http_code') == 200, r.dump_logs()
+ assert r.stats[1].get('http_code') == 200, r.dump_logs()
+ assert r.stats[0]['num_connects'] == 1, r.dump_logs()
+ assert r.stats[1]['num_connects'] == 0, r.dump_logs()
+ assert r.total_connects == 1, r.dump_logs()
+
+ # Different target hostnames must not reuse even if they resolve to the
+ # same address (Curl_peer_same_destination matches hostname + port).
+ @pytest.mark.parametrize("proto", ['http/1.1'])
+ def test_12_05_no_reuse_different_host(self, env: Env, httpd, nghttpx, proto):
+ curl = CurlClient(env=env)
+ # domain1 and domain2 are both served by the same httpd instance.
+ url1 = f'https://{env.authority_for(env.domain1, proto)}/data.json'
+ url2 = f'https://{env.authority_for(env.domain2, proto)}/data.json'
+ r = curl.http_download(urls=[url1, url2], alpn_proto=proto)
+ r.check_response(count=2, http_status=200)
+ assert r.stats[0]['num_connects'] == 1, r.dump_logs()
+ assert r.stats[1]['num_connects'] == 1, r.dump_logs()
+ assert r.total_connects == 2, r.dump_logs()
+
+ # Positive control: same host reuses one connection.
+ @pytest.mark.parametrize("proto", ['http/1.1'])
+ def test_12_06_reuse_same_host(self, env: Env, httpd, nghttpx, proto):
+ curl = CurlClient(env=env)
+ url1 = f'https://{env.authority_for(env.domain1, proto)}/data.json?a=1'
+ url2 = f'https://{env.authority_for(env.domain1, proto)}/data.json?a=2'
+ r = curl.http_download(urls=[url1, url2], alpn_proto=proto)
+ assert len(r.stats) == 2, r.dump_logs()
+ assert r.stats[0].get('http_code') == 200, r.dump_logs()
+ assert r.stats[1].get('http_code') == 200, r.dump_logs()
+ assert r.stats[0]['num_connects'] == 1, r.dump_logs()
+ assert r.stats[1]['num_connects'] == 0, r.dump_logs()
+ assert r.total_connects == 1, r.dump_logs()