Don't look into source package provides in depsolving

Fixes regressions from commit 75ec16e:
the newly added provides of to-be-built packages were being used for
dependency resolution, such as spec satifying its own buildrequires,
and matched against conflicts in installed packages.

Source packages cannot obsolete anything or provide capabilities or files
to transactions, don't add them to rpmal at all. Explicitly skip checks
against source provides, similarly to what we already did with obsoletes.

Fixes: rpm-software-management#1189

lib/depends.c

@@ -1040,17 +1040,17 @@ int rpmtsCheck(rpmts ts)
 	checkDS(ts, dcache, p, rpmteNEVRA(p), rpmteDS(p, RPMTAG_OBSOLETENAME),
 		tscolor);
 
+	/* Skip obsoletion and provides checks for source packages (ie build) */
+	if (rpmteIsSource(p))
+	    continue;
+
 	/* Check provides against conflicts in installed packages. */
 	while (rpmdsNext(provides) >= 0) {
 	    checkInstDeps(ts, dcache, p, RPMTAG_CONFLICTNAME, NULL, provides, 0);
 	    if (reqnothash && depexistsHashHasEntry(reqnothash, rpmdsNId(provides)))
 		checkInstDeps(ts, dcache, p, RPMTAG_REQUIRENAME, NULL, provides, 1);
 	}
 
-	/* Skip obsoletion checks for source packages (ie build) */
-	if (rpmteIsSource(p))
-	    continue;
-
 	/* Check package name (not provides!) against installed obsoletes */
 	checkInstDeps(ts, dcache, p, RPMTAG_OBSOLETENAME, NULL, rpmteDS(p, RPMTAG_NAME), 0);
 

lib/rpmal.c

@@ -247,6 +247,10 @@ void rpmalAdd(rpmal al, rpmte p)
     rpmalNum pkgNum;
     availablePackage alp;
 
+    /* Source packages don't provide anything to depsolving */
+    if (rpmteIsSource(p))
+	return;
+
     if (al->size == al->alloced) {
 	al->alloced += al->delta;
 	al->list = xrealloc(al->list, sizeof(*al->list) * al->alloced);