diff --git a/t/t5710-promisor-remote-capability.sh b/t/t5710-promisor-remote-capability.sh
index bf0eed9f10..b404ad9f0a 100755
--- a/t/t5710-promisor-remote-capability.sh
+++ b/t/t5710-promisor-remote-capability.sh
@@ -76,6 +76,31 @@ copy_to_lop () {
 	cp "$path" "$path2"
 }
 
+# On Windows, `pwd` returns a path like 'D:/foo/bar'. Prepend '/' to turn
+# it into '/D:/foo/bar', which is what git expects in file:// URLs on Windows.
+# On Unix, the path already starts with '/', so this is a no-op.
+pwd_path=$(pwd)
+case "$pwd_path" in
+[a-zA-Z]:*) pwd_path="/$pwd_path" ;;
+esac
+
+# Allowed characters: alphanumeric, standard path/URI (_ . ~ / : -),
+# and those percent-encoded below (% space = , ;)
+rest=$(printf "%s" "$pwd_path" | tr -d 'a-zA-Z0-9_.~/:% =,;-')
+if test -n "$rest"
+then
+	skip_all="PWD contains unsupported special characters"
+	test_done
+fi
+
+TRASH_DIRECTORY_URL="file://$pwd_path"
+
+encoded_path=$(printf "%s" "$pwd_path" |
+	       sed -e 's/%/%25/g' -e 's/ /%20/g' -e 's/=/%3D/g' \
+		   -e 's/;/%3B/g' -e 's/,/%2C/g')
+
+ENCODED_TRASH_DIRECTORY_URL="file://$encoded_path"
+
 test_expect_success "setup for testing promisor remote advertisement" '
 	# Create another bare repo called "lop" (for Large Object Promisor)
 	git init --bare lop &&
@@ -88,7 +113,7 @@ test_expect_success "setup for testing promisor remote advertisement" '
 	initialize_server 1 "$oid" &&
 
 	# Configure lop as promisor remote for server
-	git -C server remote add lop "file://$(pwd)/lop" &&
+	git -C server remote add lop "$TRASH_DIRECTORY_URL/lop" &&
 	git -C server config remote.lop.promisor true &&
 
 	git -C lop config uploadpack.allowFilter true &&
@@ -104,7 +129,7 @@ test_expect_success "clone with promisor.advertise set to 'true'" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -119,7 +144,7 @@ test_expect_success "clone with promisor.advertise set to 'false'" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -137,7 +162,7 @@ test_expect_success "clone with promisor.acceptfromserver set to 'None'" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=None \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -156,8 +181,8 @@ test_expect_success "init + fetch with promisor.advertise set to 'true'" '
 	git -C client init &&
 	git -C client config remote.lop.promisor true &&
 	git -C client config remote.lop.fetch "+refs/heads/*:refs/remotes/lop/*" &&
-	git -C client config remote.lop.url "file://$(pwd)/lop" &&
-	git -C client config remote.server.url "file://$(pwd)/server" &&
+	git -C client config remote.lop.url "$TRASH_DIRECTORY_URL/lop" &&
+	git -C client config remote.server.url "$TRASH_DIRECTORY_URL/server" &&
 	git -C client config remote.server.fetch "+refs/heads/*:refs/remotes/server/*" &&
 	git -C client config promisor.acceptfromserver All &&
 	GIT_NO_LAZY_FETCH=0 git -C client fetch --filter="blob:limit=5k" server &&
@@ -177,10 +202,10 @@ test_expect_success "clone with two promisors but only one advertised" '
 	GIT_TRACE="$(pwd)/trace" GIT_NO_LAZY_FETCH=0 git clone \
 		-c remote.unused_lop.promisor=true \
 		-c remote.unused_lop.fetch="+refs/heads/*:refs/remotes/unused_lop/*" \
-		-c remote.unused_lop.url="file://$(pwd)/unused_lop" \
+		-c remote.unused_lop.url="$TRASH_DIRECTORY_URL/unused_lop" \
 		-c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -210,11 +235,11 @@ test_expect_success "init + fetch two promisors but only one advertised" '
 	git -C client init &&
 	git -C client config remote.unused_lop.promisor true &&
 	git -C client config remote.unused_lop.fetch "+refs/heads/*:refs/remotes/unused_lop/*" &&
-	git -C client config remote.unused_lop.url "file://$(pwd)/unused_lop" &&
+	git -C client config remote.unused_lop.url "$TRASH_DIRECTORY_URL/unused_lop" &&
 	git -C client config remote.lop.promisor true &&
 	git -C client config remote.lop.fetch "+refs/heads/*:refs/remotes/lop/*" &&
-	git -C client config remote.lop.url "file://$(pwd)/lop" &&
-	git -C client config remote.server.url "file://$(pwd)/server" &&
+	git -C client config remote.lop.url "$TRASH_DIRECTORY_URL/lop" &&
+	git -C client config remote.server.url "$TRASH_DIRECTORY_URL/server" &&
 	git -C client config remote.server.fetch "+refs/heads/*:refs/remotes/server/*" &&
 	git -C client config promisor.acceptfromserver All &&
 
@@ -242,7 +267,7 @@ test_expect_success "clone with promisor.acceptfromserver set to 'KnownName'" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=KnownName \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -257,7 +282,7 @@ test_expect_success "clone with 'KnownName' and different remote names" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.serverTwo.promisor=true \
 		-c remote.serverTwo.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.serverTwo.url="file://$(pwd)/lop" \
+		-c remote.serverTwo.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=KnownName \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -294,7 +319,7 @@ test_expect_success "clone with promisor.acceptfromserver set to 'KnownUrl'" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=KnownUrl \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -311,7 +336,7 @@ test_expect_success "clone with 'KnownUrl' and different remote urls" '
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/serverTwo" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/serverTwo" \
 		-c promisor.acceptfromserver=KnownUrl \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -326,7 +351,7 @@ test_expect_success "clone with 'KnownUrl' and url not configured on the server"
 	git -C server config promisor.advertise true &&
 	test_when_finished "rm -rf client" &&
 
-	test_when_finished "git -C server config set remote.lop.url \"file://$(pwd)/lop\"" &&
+	test_when_finished "git -C server config set remote.lop.url \"$TRASH_DIRECTORY_URL/lop\"" &&
 	git -C server config unset remote.lop.url &&
 
 	# Clone from server to create a client
@@ -335,7 +360,7 @@ test_expect_success "clone with 'KnownUrl' and url not configured on the server"
 	# missing, so the remote name will be used instead which will fail.
 	test_must_fail env GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=KnownUrl \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -347,7 +372,7 @@ test_expect_success "clone with 'KnownUrl' and empty url, so not advertised" '
 	git -C server config promisor.advertise true &&
 	test_when_finished "rm -rf client" &&
 
-	test_when_finished "git -C server config set remote.lop.url \"file://$(pwd)/lop\"" &&
+	test_when_finished "git -C server config set remote.lop.url \"$TRASH_DIRECTORY_URL/lop\"" &&
 	git -C server config set remote.lop.url "" &&
 
 	# Clone from server to create a client
@@ -356,7 +381,7 @@ test_expect_success "clone with 'KnownUrl' and empty url, so not advertised" '
 	# so the remote name will be used instead which will fail.
 	test_must_fail env GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=KnownUrl \
 		--no-local --filter="blob:limit=5k" server client &&
 
@@ -380,13 +405,12 @@ test_expect_success "clone with promisor.sendFields" '
 	GIT_TRACE_PACKET="$(pwd)/trace" GIT_NO_LAZY_FETCH=0 git clone \
 		-c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter="blob:limit=5k" server client &&
 
 	# Check that fields are properly transmitted
-	ENCODED_URL=$(echo "file://$(pwd)/lop" | sed -e "s/ /%20/g") &&
-	PR1="name=lop,url=$ENCODED_URL,partialCloneFilter=blob:none" &&
+	PR1="name=lop,url=$ENCODED_TRASH_DIRECTORY_URL/lop,partialCloneFilter=blob:none" &&
 	PR2="name=otherLop,url=https://invalid.invalid,partialCloneFilter=blob:limit=10k,token=fooBar" &&
 	test_grep "clone< promisor-remote=$PR1;$PR2" trace &&
 	test_grep "clone> promisor-remote=lop;otherLop" trace &&
@@ -411,15 +435,14 @@ test_expect_success "clone with promisor.checkFields" '
 	GIT_TRACE_PACKET="$(pwd)/trace" GIT_NO_LAZY_FETCH=0 git clone \
 		-c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c remote.lop.partialCloneFilter="blob:none" \
 		-c promisor.acceptfromserver=All \
 		-c promisor.checkFields=partialcloneFilter \
 		--no-local --filter="blob:limit=5k" server client &&
 
 	# Check that fields are properly transmitted
-	ENCODED_URL=$(echo "file://$(pwd)/lop" | sed -e "s/ /%20/g") &&
-	PR1="name=lop,url=$ENCODED_URL,partialCloneFilter=blob:none" &&
+	PR1="name=lop,url=$ENCODED_TRASH_DIRECTORY_URL/lop,partialCloneFilter=blob:none" &&
 	PR2="name=otherLop,url=https://invalid.invalid,partialCloneFilter=blob:limit=10k,token=fooBar" &&
 	test_grep "clone< promisor-remote=$PR1;$PR2" trace &&
 	test_grep "clone> promisor-remote=lop" trace &&
@@ -449,7 +472,7 @@ test_expect_success "clone with promisor.storeFields=partialCloneFilter" '
 	GIT_TRACE_PACKET="$(pwd)/trace" GIT_NO_LAZY_FETCH=0 git clone \
 		-c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c remote.lop.token="fooYYY" \
 		-c remote.lop.partialCloneFilter="blob:none" \
 		-c promisor.acceptfromserver=All \
@@ -501,7 +524,7 @@ test_expect_success "clone and fetch with --filter=auto" '
 
 	GIT_TRACE_PACKET="$(pwd)/trace" GIT_NO_LAZY_FETCH=0 git clone \
 		-c remote.lop.promisor=true \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter=auto server client 2>err &&
 
@@ -558,7 +581,7 @@ test_expect_success "clone with promisor.advertise set to 'true' but don't delet
 	# Clone from server to create a client
 	GIT_NO_LAZY_FETCH=0 git clone -c remote.lop.promisor=true \
 		-c remote.lop.fetch="+refs/heads/*:refs/remotes/lop/*" \
-		-c remote.lop.url="file://$(pwd)/lop" \
+		-c remote.lop.url="$TRASH_DIRECTORY_URL/lop" \
 		-c promisor.acceptfromserver=All \
 		--no-local --filter="blob:limit=5k" server client &&