conf: drop the angle brackets from if, infer from the value

The block format spells conditions as bare strings everywhere else, so
requiring `if = "<usr/foo>"` left one sigil behind, carried over from
the line-based `if:` token.  A namespace separator already tells the two
apart: a value with a '/' is a condition, anything else is a service
name.

svc_ifthen() picks its mode from the start of the statement and applies
it to the whole, so a statement naming both kinds cannot be evaluated.
That is now an error, as are the old angle brackets, and either one
skips the block:

    /etc/finit.conf: mixed: if: cannot mix a service name with a
    condition in 'anchor,usr/enable-me', a statement must be all of
    one kind, skipping

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/Makefile.am

@@ -32,6 +32,7 @@ EXTRA_DIST		+= add-remove-dynamic-service-sub-config.sh
 EXTRA_DIST		+= bootstrap-crash.sh
 EXTRA_DIST		+= cond-start-task.sh
 EXTRA_DIST		+= conf-format.sh
+EXTRA_DIST		+= conf-if.sh
 EXTRA_DIST		+= conf-template.sh
 EXTRA_DIST		+= script-timeout.sh
 EXTRA_DIST		+= crashing.sh
@@ -79,6 +80,7 @@ TESTS			+= add-remove-dynamic-service-sub-config.sh
 TESTS			+= bootstrap-crash.sh
 TESTS			+= cond-start-task.sh
 TESTS			+= conf-format.sh
+TESTS			+= conf-if.sh
 TESTS			+= conf-template.sh
 TESTS			+= script-timeout.sh
 TESTS			+= crashing.sh

test/conf-if.sh

@@ -0,0 +1,95 @@
+#!/bin/sh
+# Verify the block format 'if' setting: a value with a namespace
+# separator is a condition, checked at runtime, anything else is a
+# service name, checked when the .conf is read.  The two cannot be
+# combined, and the legacy angle brackets are rejected.
+set -eu
+
+TEST_DIR=$(dirname "$0")
+
+# shellcheck disable=SC2034
+BOOTSTRAP="service anchor {
+    runlevel = \"S12345\"
+    command  = \"serv -np -i anchor\"
+}
+service byname {
+    runlevel = \"S12345\"
+    if       = \"anchor\"
+    command  = \"serv -np -i byname\"
+}
+service noname {
+    runlevel = \"S12345\"
+    if       = \"nosuchservice\"
+    command  = \"serv -np -i noname\"
+}
+service negated {
+    runlevel = \"S12345\"
+    if       = \"!anchor\"
+    command  = \"serv -np -i negated\"
+}
+service bycond {
+    runlevel = \"S12345\"
+    if       = \"usr/enable-me\"
+    command  = \"serv -np -i bycond\"
+}
+service brackets {
+    runlevel = \"S12345\"
+    if       = \"<usr/enable-me>\"
+    command  = \"serv -np -i brackets\"
+}
+service mixed {
+    runlevel = \"S12345\"
+    if       = \"anchor,usr/enable-me\"
+    command  = \"serv -np -i mixed\"
+}"
+
+# initctl status prints a detail block for a single match and a table
+# only for several, so count lines in the full listing instead.
+assert_loaded()
+{
+    assert "Service $1 loaded: $2" \
+	   "$(texec initctl -t status | awk -v n="$1" '$2 == n' | wc -l)" -eq "$2"
+}
+
+test_teardown()
+{
+    say "Running test teardown."
+    run "initctl cond clear enable-me" || true
+}
+
+# shellcheck source=/dev/null
+. "$TEST_DIR/lib/setup.sh"
+
+say 'A bare value names a service, resolved when the .conf is read'
+retry 'assert_loaded byname 1'
+
+say 'A service that is not known keeps the block out of the config'
+assert_loaded noname 0
+
+say 'Negation of a known service keeps the block out too'
+assert_loaded negated 0
+
+say 'A value with a namespace separator is a condition, so the block is'
+say 'loaded, but held until the condition is asserted'
+assert_loaded bycond 1
+assert_status bycond halted
+
+run "initctl cond set enable-me"
+retry 'assert_status bycond running'
+
+# 'if' qualifies the block, it does not track the condition, so
+# clearing it does not stop a running service.  The qualification is
+# re-read when the configuration is, i.e. on reload.
+run "initctl cond clear enable-me"
+run "initctl reload"
+retry 'assert_status bycond halted'
+
+say 'Angle brackets belong to the line-based format, the block is rejected'
+assert_loaded brackets 0
+
+say 'A service name and a condition are checked at different times, so'
+say 'mixing them in one statement is rejected'
+assert_loaded mixed 0
+
+say 'Rejecting a block leaves the rest of the file alone'
+assert_loaded anchor 1