lib/config: set defaults for user full name

This just copies code from from the CLI into the library. New test
infrastructure is needed because apparently we have never tested this
code path.

lib/config.cc

@@ -22,6 +22,8 @@
 #include "notmuch-private.h"
 #include "database-private.h"
 
+#include <pwd.h>
+
 static const std::string CONFIG_PREFIX = "C";
 
 struct _notmuch_config_list {
@@ -451,6 +453,41 @@ notmuch_config_get_bool (notmuch_database_t *notmuch, notmuch_config_key_t key,
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+static const char *
+_get_name_from_passwd_file (void *ctx)
+{
+    long pw_buf_size;
+    char *pw_buf;
+    struct passwd passwd, *ignored;
+    const char *name;
+    int e;
+
+    pw_buf_size = sysconf (_SC_GETPW_R_SIZE_MAX);
+    if (pw_buf_size == -1) pw_buf_size = 64;
+    pw_buf = (char *) talloc_size (ctx, pw_buf_size);
+
+    while ((e = getpwuid_r (getuid (), &passwd, pw_buf,
+			    pw_buf_size, &ignored)) == ERANGE) {
+	pw_buf_size = pw_buf_size * 2;
+	pw_buf = (char *) talloc_zero_size (ctx, pw_buf_size);
+    }
+
+    if (e == 0) {
+	char *comma = strchr (passwd.pw_gecos, ',');
+	if (comma)
+	    name = talloc_strndup (ctx, passwd.pw_gecos,
+				   comma - passwd.pw_gecos);
+	else
+	    name = talloc_strdup (ctx, passwd.pw_gecos);
+    } else {
+	name = talloc_strdup (ctx, "");
+    }
+
+    talloc_free (pw_buf);
+
+    return name;
+}
+
 static const char *
 _notmuch_config_key_to_string (notmuch_config_key_t key)
 {
@@ -486,6 +523,7 @@ static const char *
 _notmuch_config_default (notmuch_database_t *notmuch, notmuch_config_key_t key)
 {
     char *path;
+    const char *name;
 
     switch (key) {
     case NOTMUCH_CONFIG_DATABASE_PATH:
@@ -505,10 +543,18 @@ _notmuch_config_default (notmuch_database_t *notmuch, notmuch_config_key_t key)
 	return "inbox;unread";
     case NOTMUCH_CONFIG_SYNC_MAILDIR_FLAGS:
 	return "true";
+    case NOTMUCH_CONFIG_USER_NAME:
+	name = getenv ("NAME");
+	if (name)
+	    name = talloc_strdup (notmuch, name);
+	else
+	    name = _get_name_from_passwd_file (notmuch);
+
+	return name;
+	break;
     case NOTMUCH_CONFIG_HOOK_DIR:
     case NOTMUCH_CONFIG_BACKUP_DIR:
     case NOTMUCH_CONFIG_NEW_IGNORE:
-    case NOTMUCH_CONFIG_USER_NAME:
     case NOTMUCH_CONFIG_PRIMARY_EMAIL:
     case NOTMUCH_CONFIG_OTHER_EMAIL:
 	return NULL;

test/T590-libconfig.sh

@@ -384,6 +384,9 @@ cat c_head - c_tail <<'EOF' | test_C ${MAIL_DIR} '' %NULL%
     }
 }
 EOF
+
+notmuch_passwd_sanitize < OUTPUT > OUTPUT.clean
+
 cat <<'EOF' >EXPECTED
 == stdout ==
 MAIL_DIR
@@ -396,11 +399,11 @@ NULL
 true
 NULL
 NULL
-NULL
+USER_FULL_NAME
 == stderr ==
 EOF
 unset MAILDIR
-test_expect_equal_file EXPECTED OUTPUT
+test_expect_equal_file EXPECTED OUTPUT.clean
 
 backup_database
 test_begin_subtest "override config from \${NOTMUCH_CONFIG}"
@@ -727,6 +730,8 @@ cat c_head2 - c_tail <<'EOF' | test_C ${MAIL_DIR} /nonexistent %NULL%
     }
 }
 EOF
+
+notmuch_passwd_sanitize < OUTPUT > OUTPUT.clean
 cat <<'EOF' >EXPECTED
 == stdout ==
 MAIL_DIR
@@ -739,10 +744,10 @@ NULL
 true
 NULL
 NULL
-NULL
+USER_FULL_NAME
 == stderr ==
 EOF
-test_expect_equal_file EXPECTED OUTPUT
+test_expect_equal_file EXPECTED OUTPUT.clean
 
 backup_database
 test_begin_subtest "override config from \${HOME}/.notmuch-config (ndlc)"

test/test-lib.sh

@@ -694,6 +694,13 @@ notmuch_built_with_sanitize ()
     sed 's/^built_with[.]\(.*\)=.*$/built_with.\1=something/'
 }
 
+notmuch_passwd_sanitize ()
+{
+    local user=$(id -un)
+    local full_name=$(getent passwd $user | cut -d: -f 5 | cut -d, -f1)
+    sed "s/$full_name/USER_FULL_NAME/"
+}
+
 notmuch_config_sanitize ()
 {
     notmuch_dir_sanitize | notmuch_built_with_sanitize