[PATCH 14/22] support splitting mail from database location.

[David Bremner <david@tethera.net>]

Introduce a new configuration value for the mail root, and use it in
preference to the database.path (which previously implied the mail was
also in this location.

Further changes to the CLI will be needed to work in this split
configuration.
---
 doc/man1/notmuch-config.rst | 14 ++++--
 lib/config.cc               | 11 +++--
 lib/database.cc             |  2 +-
 lib/message-file.c          |  2 +-
 lib/message.cc              |  2 +-
 lib/notmuch.h               |  1 +
 lib/open.cc                 |  5 +++
 test/T055-path-config.sh    | 90 +++++++++++++++++++++++++++++++++++++
 test/T590-libconfig.sh      |  1 +
 9 files changed, 119 insertions(+), 9 deletions(-)
 create mode 100755 test/T055-path-config.sh

diff --git a/doc/man1/notmuch-config.rst b/doc/man1/notmuch-config.rst
index bc597957..99030a41 100644
--- a/doc/man1/notmuch-config.rst
+++ b/doc/man1/notmuch-config.rst
@@ -43,12 +43,20 @@ configuration file and corresponding database.
 The available configuration items are described below.
 
 **database.path**
+    Notmuch will store its database within a
+    sub-directory of the path configured here named ``.notmuch``.
+
+    Default: ``$MAILDIR`` variable if set, otherwise ``$HOME/mail``.
+
+**database.mail_root**
     The top-level directory where your mail currently exists and to
     where mail will be delivered in the future. Files should be
-    individual email messages. Notmuch will store its database within
-    a sub-directory of the path configured here named ``.notmuch``.
+    individual email messages.
 
-    Default: ``$MAILDIR`` variable if set, otherwise ``$HOME/mail``.
+    History: this configuration value was introduced in notmuch 0.32.
+
+    Default: For compatibility with older configurations, the value of
+    database.path is used if database.mail\_root is unset.
 
 **database.hook_dir**
 
diff --git a/lib/config.cc b/lib/config.cc
index 99b75e7b..3b8f1092 100644
--- a/lib/config.cc
+++ b/lib/config.cc
@@ -390,6 +390,8 @@ _notmuch_config_key_to_string (notmuch_config_key_t key) {
     switch (key) {
     case NOTMUCH_CONFIG_DATABASE_PATH:
 	return "database.path";
+    case NOTMUCH_CONFIG_MAIL_ROOT:
+	return "database.mail_root";
     case NOTMUCH_CONFIG_HOOK_DIR:
 	return "database.hook_dir";
     case NOTMUCH_CONFIG_EXCLUDE_TAGS:
@@ -412,18 +414,21 @@ _notmuch_config_key_to_string (notmuch_config_key_t key) {
 }
 
 static const char *
-_notmuch_config_default (void *ctx, notmuch_config_key_t key) {
+_notmuch_config_default (notmuch_database_t *notmuch, notmuch_config_key_t key) {
     char *path;
 
     switch (key) {
     case NOTMUCH_CONFIG_DATABASE_PATH:
 	path = getenv ("MAILDIR");
 	if (path)
-	    path = talloc_strdup (ctx, path);
+	    path = talloc_strdup (notmuch, path);
 	else
-	    path = talloc_asprintf (ctx, "%s/mail",
+	    path = talloc_asprintf (notmuch, "%s/mail",
 				    getenv ("HOME"));
 	return path;
+    case NOTMUCH_CONFIG_MAIL_ROOT:
+	/* by default, mail root is the same as database path */
+	return notmuch_database_get_path (notmuch);
     case NOTMUCH_CONFIG_EXCLUDE_TAGS:
 	return "";
     case NOTMUCH_CONFIG_NEW_TAGS:
diff --git a/lib/database.cc b/lib/database.cc
index afa8b754..1d8839a5 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -1345,7 +1345,7 @@ _notmuch_database_relative_path (notmuch_database_t *notmuch,
     const char *db_path, *relative;
     unsigned int db_path_len;
 
-    db_path = notmuch_database_get_path (notmuch);
+    db_path = notmuch_config_get (notmuch, NOTMUCH_CONFIG_MAIL_ROOT);
     db_path_len = strlen (db_path);
 
     relative = path;
diff --git a/lib/message-file.c b/lib/message-file.c
index 311bd478..a23493f1 100644
--- a/lib/message-file.c
+++ b/lib/message-file.c
@@ -64,7 +64,7 @@ _notmuch_message_file_open_ctx (notmuch_database_t *notmuch,
     if (unlikely (message == NULL))
 	return NULL;
 
-    const char *prefix = notmuch_database_get_path (notmuch);
+    const char *prefix = notmuch_config_get (notmuch, NOTMUCH_CONFIG_MAIL_ROOT);
     if (prefix == NULL)
 	goto FAIL;
 
diff --git a/lib/message.cc b/lib/message.cc
index 1bea90f0..35f0b87a 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -1098,7 +1098,7 @@ _notmuch_message_ensure_filename_list (notmuch_message_t *message)
 
 	*colon = '\0';
 
-	db_path = notmuch_database_get_path (message->notmuch);
+	db_path = notmuch_config_get (message->notmuch, NOTMUCH_CONFIG_MAIL_ROOT);
 
 	directory = _notmuch_database_get_directory_path (local,
 							  message->notmuch,
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 37d7581f..374d3af9 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -2473,6 +2473,7 @@ notmuch_config_list_destroy (notmuch_config_list_t *config_list);
 typedef enum _notmuch_config_key {
     NOTMUCH_CONFIG_FIRST,
     NOTMUCH_CONFIG_DATABASE_PATH = NOTMUCH_CONFIG_FIRST,
+    NOTMUCH_CONFIG_MAIL_ROOT,
     NOTMUCH_CONFIG_HOOK_DIR,
     NOTMUCH_CONFIG_EXCLUDE_TAGS,
     NOTMUCH_CONFIG_NEW_TAGS,
diff --git a/lib/open.cc b/lib/open.cc
index 4e8ab3b4..2f65198d 100644
--- a/lib/open.cc
+++ b/lib/open.cc
@@ -252,6 +252,11 @@ _choose_xapian_path (void *ctx, const char *database_path, const char **xapian_p
     if (status)
 	goto DONE;
 
+    trial_path = talloc_asprintf (ctx, "%s/xapian", database_path);
+    status = _trial_open (trial_path, message_ptr);
+    if (status != NOTMUCH_STATUS_PATH_ERROR)
+	goto DONE;
+
     notmuch_path = talloc_asprintf (ctx, "%s/.notmuch", database_path);
     status = _db_dir_exists (notmuch_path, message_ptr);
     if (status)
diff --git a/test/T055-path-config.sh b/test/T055-path-config.sh
new file mode 100755
index 00000000..c6920ca9
--- /dev/null
+++ b/test/T055-path-config.sh
@@ -0,0 +1,90 @@
+#!/usr/bin/env bash
+test_description='Configuration of mail-root and database path'
+. $(dirname "$0")/test-lib.sh || exit 1
+
+backup_config () {
+    local test_name=$(basename $0 .sh)
+    cp ${NOTMUCH_CONFIG} notmuch-config-backup.${test_name}
+}
+
+restore_config () {
+    local test_name=$(basename $0 .sh)
+    export NOTMUCH_CONFIG="${TMP_DIRECTORY}/notmuch-config"
+    unset CONFIG_PATH
+    unset DATABASE_PATH
+    unset NOTMUCH_PROFILE
+    cp notmuch-config-backup.${test_name} ${NOTMUCH_CONFIG}
+}
+
+split_config () {
+    local dir
+    backup_config
+    dir="$TMP_DIRECTORY/database.$test_count"
+    rm -rf $dir
+    mkdir $dir
+    notmuch config set database.path $dir
+    notmuch config set database.mail_root $MAIL_DIR
+    DATABASE_PATH=$dir
+}
+
+
+
+for config in traditional split; do
+    # start each set of tests with a known set of messages
+    add_email_corpus
+
+    case $config in
+	traditional)
+	    backup_config
+	    ;;
+	split)
+	    split_config
+	    mv mail/.notmuch/xapian $DATABASE_PATH
+	    ;;
+    esac
+
+    test_begin_subtest "count ($config)"
+    output=$(notmuch count '*')
+    test_expect_equal "$output" '52'
+
+    test_begin_subtest "count+tag ($config)"
+    tag="tag${RANDOM}"
+    notmuch tag +$tag '*'
+    output=$(notmuch count tag:$tag)
+    notmuch tag -$tag '*'
+    test_expect_equal "$output" '52'
+
+    test_begin_subtest "address ($config)"
+    notmuch address --deduplicate=no --sort=newest-first --output=sender --output=recipients path:foo >OUTPUT
+    cat <<EOF >EXPECTED
+Carl Worth <cworth@cworth.org>
+notmuch@notmuchmail.org
+EOF
+    test_expect_equal_file EXPECTED OUTPUT
+
+    test_begin_subtest "dump ($config)"
+    notmuch dump is:attachment and is:signed | sort > OUTPUT
+    cat <<EOF > EXPECTED
+#notmuch-dump batch-tag:3 config,properties,tags
++attachment +inbox +signed +unread -- id:20091118005829.GB25380@dottiness.seas.harvard.edu
++attachment +inbox +signed +unread -- id:20091118010116.GC25380@dottiness.seas.harvard.edu
+EOF
+    test_expect_equal_file EXPECTED OUTPUT
+
+    test_begin_subtest "dump + tag + restore ($config)"
+    notmuch dump '*' > EXPECTED
+    notmuch tag -inbox '*'
+    notmuch restore < EXPECTED
+    notmuch dump > OUTPUT
+    test_expect_equal_file EXPECTED OUTPUT
+
+    test_begin_subtest "reindex ($config)"
+    notmuch search --output=messages '*' > EXPECTED
+    notmuch reindex '*'
+    notmuch search --output=messages '*' > OUTPUT
+    test_expect_equal_file EXPECTED OUTPUT
+
+    restore_config
+done
+
+test_done
diff --git a/test/T590-libconfig.sh b/test/T590-libconfig.sh
index 4e510e97..5cf70987 100755
--- a/test/T590-libconfig.sh
+++ b/test/T590-libconfig.sh
@@ -364,6 +364,7 @@ EOF
 cat <<'EOF' >EXPECTED
 == stdout ==
 MAIL_DIR
+MAIL_DIR
 MAIL_DIR/.notmuch/hooks
 
 inbox;unread
-- 
2.30.1