lib: fix regression for installing packages by pkgver

Fixes a regression introduces by a634e82, where when installing already
installed packages by pkgver only the package would be used to query the
repository pool instead of the pkgver. As a result xbps-install
would print "package already installed" instead of "package not found"
messages.

Resolved by only switching to the provider package name when the pkgver
refers to an installed virtual package, otherwise the supplied
pkgver/pkgname/pkgdep will be used.

Author: Duncaen

lib/transaction_ops.c

@@ -23,7 +23,6 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -55,13 +54,13 @@
 static int
 trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool force)
 {
+	char buf[XBPS_NAME_SIZE];
 	xbps_dictionary_t pkg_pkgdb = NULL, pkg_repod = NULL, vpkg_pkgdb = NULL;
 	xbps_object_t obj;
 	xbps_array_t pkgs;
 	pkg_state_t state = 0;
 	xbps_trans_type_t ttype;
 	const char *repoloc, *repopkgver, *instpkgver, *pkgname;
-	char buf[XBPS_NAME_SIZE] = {0};
 	bool autoinst = false;
 	int rv = 0;
 
@@ -89,8 +88,16 @@ trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool force)
 		// virtual package installed, if there is no real package in
 		// the rpool, we are keeping the virtual package.
 		pkg_repod = xbps_rpool_get_pkg(xhp, pkg);
-		if (!pkg_repod)
+		if (!pkg_repod) {
 			pkg_pkgdb = vpkg_pkgdb;
+			// if we are using the installed virtual package,
+			// use the provider to query the repository pool.
+			if (!xbps_dictionary_get_cstring_nocopy(
+			        pkg_pkgdb, "pkgname", &pkg)) {
+				xbps_error_printf("missing `pkgname` property\n");
+				return EINVAL;
+			}
+		}
 	}
 	if (pkg_pkgdb) {
 		// package already installed
@@ -99,10 +106,6 @@ trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool force)
 		} else {
 			ttype = XBPS_TRANS_UPDATE;
 		}
-		if (!xbps_dictionary_get_cstring_nocopy(pkg_pkgdb, "pkgname", &pkgname)) {
-			xbps_error_printf("missing `pkgname` property\n");
-			return EINVAL;
-		}
 		if (xbps_dictionary_get(pkg_pkgdb, "repolock")) {
 			struct xbps_repo *repo;
 			/* find update from repo */
@@ -112,10 +115,10 @@ trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool force)
 				/* not found */
 				return ENOENT;
 			}
-			pkg_repod = xbps_repo_get_pkg(repo, pkgname);
+			pkg_repod = xbps_repo_get_pkg(repo, pkg);
 		} else {
 			/* find update from rpool */
-			pkg_repod = xbps_rpool_get_pkg(xhp, pkgname);
+			pkg_repod = xbps_rpool_get_pkg(xhp, pkg);
 		}
 	} else {
 		ttype = XBPS_TRANS_INSTALL;