Let pacman specify GnuPG's home directory.

GnuPG looks for configuration files and keyrings in its home directory.
For a user, that is typically ~/.gnupg.
This patch causes pacman to use /etc/pacman.d/gnupg/ as the default
GnuPG home.  One may override the default using --gpgdir on the command-line
or GPGDir in pacman's configuration file.

Signed-off-by: Chris Brannon <cmbrannon@cox.net>
Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

doc/pacman.8.txt

@@ -149,6 +149,13 @@ Options
 	Display debug messages. When reporting bugs, this option is recommended
 	to be used.
 
+*\--gpgdir* <dir>::
+	Specify a directory of files used by GnuPG to verify package signatures.
+	This directory should contain two files: `pubring.gpg` and `trustdb.gpg`.
+	`pubring.gpg` holds the public keys of all packagers. `trustdb.gpg`
+	contains a so-called trust database, which specifies that the keys are
+	authentic and trusted.
+
 *\--logfile* <file>::
 	Specify an alternate log file. This is an absolute path, regardless of
 	the installation root setting.

doc/pacman.conf.5.txt

@@ -69,6 +69,15 @@ Options
 	to the first cache directory with write access. *NOTE*: this is an absolute
 	path, the root path is not automatically prepended.
 
+*GPGDir =* path/to/gpg/dir::
+	Overrides the default location of the directory containing configuration
+	files for GnuPG. A typical default is `{sysconfdir}/pacman.d/gnupg/`.
+	This directory should contain two files: `pubring.gpg` and `trustdb.gpg`.
+	`pubring.gpg` holds the public keys of all packagers. `trustdb.gpg`
+	contains a so-called trust database, which specifies that the keys are
+	authentic and trusted.
+	*NOTE*: this is an absolute path, the root path is not automatically
+	prepended.
 
 *LogFile =* '/path/to/file'::
 	Overrides the default location of the pacman log file. A typical default

src/pacman/Makefile.am

@@ -1,6 +1,7 @@
 # paths set at make time
 conffile  = ${sysconfdir}/pacman.conf
 dbpath    = ${localstatedir}/lib/pacman/
+gpgdir    = ${sysconfdir}/pacman.d/gnupg/
 cachedir  = ${localstatedir}/cache/pacman/pkg/
 logfile   = ${localstatedir}/log/pacman.log
 
@@ -10,6 +11,7 @@ DEFS = -DLOCALEDIR=\"@localedir@\" \
        -DCONFFILE=\"$(conffile)\" \
        -DROOTDIR=\"$(ROOTDIR)\" \
        -DDBPATH=\"$(dbpath)\" \
+       -DGPGDIR=\"$(gpgdir)\" \
        -DCACHEDIR=\"$(cachedir)\" \
        -DLOGFILE=\"$(logfile)\" \
        @DEFS@

src/pacman/conf.h

@@ -40,6 +40,7 @@ typedef struct __config_t {
 	char *rootdir;
 	char *dbpath;
 	char *logfile;
+	char *gpgdir;
 	/* TODO how to handle cachedirs? */
 
 	unsigned short op_q_isfile;
@@ -106,7 +107,8 @@ enum {
 	OP_NEEDED,
 	OP_ASEXPLICIT,
 	OP_ARCH,
-	OP_PRINTFORMAT
+	OP_PRINTFORMAT,
+	OP_GPGDIR
 };
 
 /* clean method */

src/pacman/pacman.c

@@ -202,6 +202,7 @@ static void usage(int op, const char * const myname)
 		addlist(_("      --cachedir <dir> set an alternate package cache location\n"));
 		addlist(_("      --config <path>  set an alternate configuration file\n"));
 		addlist(_("      --debug          display debug messages\n"));
+		addlist(_("      --gpgdir <path>  set an alternate home directory for GnuPG\n"));
 		addlist(_("      --logfile <path> set an alternate log file\n"));
 		addlist(_("      --noconfirm      do not ask for any confirmation\n"));
 	}
@@ -385,6 +386,17 @@ static void setlibpaths(void)
 			}
 		}
 
+		/* Set GnuPG's home directory.  This is not relative to rootdir, even if
+		 * rootdir is defined. Reasoning: gpgdir contains configuration data. */
+		if(config->gpgdir) {
+			ret = alpm_option_set_signaturedir(config->gpgdir);
+			if(ret != 0) {
+				pm_printf(PM_LOG_ERROR, _("problem setting gpgdir '%s' (%s)\n"),
+						config->gpgdir, alpm_strerrorlast());
+				cleanup(ret);
+			}
+		}
+
 		/* add a default cachedir if one wasn't specified */
 		if(alpm_option_get_cachedirs() == NULL) {
 			alpm_option_add_cachedir(CACHEDIR);
@@ -500,6 +512,9 @@ static int parsearg_global(int opt)
 			/* progress bars get wonky with debug on, shut them off */
 			config->noprogressbar = 1;
 			break;
+		case OP_GPGDIR:
+			config->gpgdir = strdup(optarg);
+			break;
 		case OP_LOGFILE:
 			check_optarg();
 			config->logfile = strndup(optarg, PATH_MAX);
@@ -701,6 +716,7 @@ static int parseargs(int argc, char *argv[])
 		{"asexplicit",     no_argument,   0, OP_ASEXPLICIT},
 		{"arch",       required_argument, 0, OP_ARCH},
 		{"print-format", required_argument, 0, OP_PRINTFORMAT},
+		{"gpgdir",     required_argument, 0, OP_GPGDIR},
 		{0, 0, 0, 0}
 	};
 
@@ -1017,6 +1033,11 @@ static int _parse_options(const char *key, char *value,
 				config->rootdir = strdup(value);
 				pm_printf(PM_LOG_DEBUG, "config: rootdir: %s\n", value);
 			}
+		} else if (strcmp(key, "GPGDir") == 0) {
+			if(!config->gpgdir) {
+				config->gpgdir = strdup(value);
+				pm_printf(PM_LOG_DEBUG, "config: gpgdir: %s\n", value);
+			}
 		} else if (strcmp(key, "LogFile") == 0) {
 			if(!config->logfile) {
 				config->logfile = strdup(value);
@@ -1340,6 +1361,7 @@ int main(int argc, char *argv[])
 	/* define paths to reasonable defaults */
 	alpm_option_set_root(ROOTDIR);
 	alpm_option_set_dbpath(DBPATH);
+	alpm_option_set_signaturedir(GPGDIR);
 	alpm_option_set_logfile(LOGFILE);
 
 	/* Priority of options: