Rename td2pool as rpmtdToPool, export and optimize

- Using rpmtd iteration for this is slow and stupid as we keep
  pointlessly re-re-re-re-re-validating the tag type and indexes.
- Change argument order to source -> destination
- Move to rpmtd.c where it belongs and make public with a decent
  name. Not sure if this is the kind of an API we really want to make
  public but ... at least for now it'll do.

lib/rpmfi.c

@@ -1064,22 +1064,12 @@ rpmfi rpmfiFree(rpmfi fi)
     return NULL;
 }
 
-static rpmsid * td2pool(rpmstrPool pool, rpmtd td)
-{
-    rpmsid *sids = xmalloc(sizeof(*sids) * rpmtdCount(td));
-    const char *str;
-    int i = 0;
-    while ((str = rpmtdNextString(td)))
-	sids[i++] = rpmstrPoolId(pool, str, 1);
-    return sids;
-}
-
 static rpmsid * tag2pool(rpmstrPool pool, Header h, rpmTag tag)
 {
     rpmsid *sids = NULL;
     struct rpmtd_s td;
     if (headerGet(h, tag, &td, HEADERGET_MINMEM)) {
-	sids = td2pool(pool, &td);
+	sids = rpmtdToPool(&td, pool);
 	rpmtdFreeData(&td);
     }
     return sids;
@@ -1232,8 +1222,8 @@ rpmfi rpmfiNewPool(rpmstrPool pool, Header h, rpmTagVal tagN, rpmfiFlags flags)
 	    /* init the file triplet data */
 	    fi->fc = rpmtdCount(&bn);
 	    fi->dc = rpmtdCount(&dn);
-	    fi->bnid = td2pool(fi->pool, &bn);
-	    fi->dnid = td2pool(fi->pool, &dn);
+	    fi->bnid = rpmtdToPool(&bn, fi->pool);
+	    fi->dnid = rpmtdToPool(&dn, fi->pool);
 	    /* steal index data from the td (pooh...) */
 	    fi->dil = dx.data;
 	    dx.data = NULL;

lib/rpmtd.c

@@ -3,6 +3,7 @@
 #include <rpm/rpmtd.h>
 #include <rpm/rpmstring.h>
 #include <rpm/rpmpgp.h>
+#include <rpm/rpmstrpool.h>
 #include "lib/misc.h"		/* format function prototypes */
 
 #include "debug.h"
@@ -444,3 +445,21 @@ rpmtd rpmtdDup(rpmtd td)
 
     return newtd;
 }
+
+rpmsid * rpmtdToPool(rpmtd td, rpmstrPool pool)
+{
+    rpmsid *sids = NULL;
+
+    if (pool && td) {
+	const char **strings = td->data;
+	switch (td->type) {
+	case RPM_STRING_ARRAY_TYPE:
+	case RPM_I18NSTRING_TYPE:
+	    sids = xmalloc(td->count * sizeof(*sids));
+	    for (rpm_count_t i = 0; i < td->count; i++)
+		sids[i] = rpmstrPoolId(pool, strings[i], 1);
+	    break;
+	}
+    }
+    return sids;
+}

lib/rpmtd.h

@@ -356,6 +356,14 @@ int rpmtdFromArgi(rpmtd td, rpmTagVal tag, ARGI_t argi);
  */
 rpmtd rpmtdDup(rpmtd td);
 
+/* \ingroup rpmtd
+ * Push string array container contents to a string pool, return string ids.
+ * @param td		Tag data container
+ * @param pool		String pool
+ * @return		Array of string id's (malloced)
+ */
+rpmsid * rpmtdToPool(rpmtd td, rpmstrPool pool);
+
 #ifdef __cplusplus
 }
 #endif