diff --git a/ext/rtree/rtree.c b/ext/rtree/rtree.c
index 73d06614f4..78849bd555 100644
--- a/ext/rtree/rtree.c
+++ b/ext/rtree/rtree.c
@@ -3755,49 +3755,45 @@ static int rtreeInit(
 ** <num-dimension>*2 coordinates.
 */
 static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
-  char *zText = 0;
   RtreeNode node;
   Rtree tree;
   int ii;
+  int nData;
+  int errCode;
+  sqlite3_str *pOut;
 
   UNUSED_PARAMETER(nArg);
   memset(&node, 0, sizeof(RtreeNode));
   memset(&tree, 0, sizeof(Rtree));
   tree.nDim = (u8)sqlite3_value_int(apArg[0]);
+  if( tree.nDim<1 || tree.nDim>5 ) return;
   tree.nDim2 = tree.nDim*2;
   tree.nBytesPerCell = 8 + 8 * tree.nDim;
   node.zData = (u8 *)sqlite3_value_blob(apArg[1]);
+  nData = sqlite3_value_bytes(apArg[1]);
+  if( nData<4 ) return;
+  if( nData<NCELL(&node)*tree.nBytesPerCell ) return;
 
+  pOut = sqlite3_str_new(0);
   for(ii=0; ii<NCELL(&node); ii++){
-    char zCell[512];
-    int nCell = 0;
     RtreeCell cell;
     int jj;
 
     nodeGetCell(&tree, &node, ii, &cell);
-    sqlite3_snprintf(512-nCell,&zCell[nCell],"%lld", cell.iRowid);
-    nCell = (int)strlen(zCell);
+    if( ii>0 ) sqlite3_str_append(pOut, " ", 1);
+    sqlite3_str_appendf(pOut, "{%lld", cell.iRowid);
     for(jj=0; jj<tree.nDim2; jj++){
 #ifndef SQLITE_RTREE_INT_ONLY
-      sqlite3_snprintf(512-nCell,&zCell[nCell], " %g",
-                       (double)cell.aCoord[jj].f);
+      sqlite3_str_appendf(pOut, " %g", (double)cell.aCoord[jj].f);
 #else
-      sqlite3_snprintf(512-nCell,&zCell[nCell], " %d",
-                       cell.aCoord[jj].i);
+      sqlite3_str_appendf(pOut, " %d", cell.aCoord[jj].i);
 #endif
-      nCell = (int)strlen(zCell);
-    }
-
-    if( zText ){
-      char *zTextNew = sqlite3_mprintf("%s {%s}", zText, zCell);
-      sqlite3_free(zText);
-      zText = zTextNew;
-    }else{
-      zText = sqlite3_mprintf("{%s}", zCell);
     }
+    sqlite3_str_append(pOut, "}", 1);
   }
-  
-  sqlite3_result_text(ctx, zText, -1, sqlite3_free);
+  errCode = sqlite3_str_errcode(pOut);
+  sqlite3_result_text(ctx, sqlite3_str_finish(pOut), -1, sqlite3_free);
+  sqlite3_result_error_code(ctx, errCode);
 }
 
 /* This routine implements an SQL function that returns the "depth" parameter
diff --git a/manifest b/manifest
index bb4a5cfc1d..8d63829245 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Enhance\sthe\sVACUUM\sINTO\scommand\sso\sthat\sit\sworks\son\sread-only\sdatabases.
-D 2019-03-19T20:42:42.516
+C Enhance\sthe\srtreenode()\sfunction\sof\srtree\s(used\sfor\stesting)\sso\sthat\sit\nuses\sthe\snewer\ssqlite3_str\sobject\sfor\sbetter\sperformance\sand\simproved\nerror\sreporting.
+D 2019-03-20T11:16:09.278
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -370,7 +370,7 @@ F ext/repair/test/checkindex01.test b530f141413b587c9eb78ff734de6bb79bc3515c3350
 F ext/repair/test/test.tcl 686d76d888dffd021f64260abf29a55c57b2cedfa7fc69150b42b1d6119aac3c
 F ext/rtree/README 6315c0d73ebf0ec40dedb5aa0e942bc8b54e3761
 F ext/rtree/geopoly.c 061432bddc38c4c10c7e4ce940d581c886d65bb5814b4b65b46ad046aa85eaa2
-F ext/rtree/rtree.c 57729cc19f3832e5f9051556af44ed264b5bd54b01543cd7e50d5143817b964c
+F ext/rtree/rtree.c f2ce90120f3e2e01f8a510a227cafbea224c08ba2bf6809b0139c671de2873dc
 F ext/rtree/rtree.h 4a690463901cb5e6127cf05eb8e642f127012fd5003830dbc974eca5802d9412
 F ext/rtree/rtree1.test 7573134f1b4f59df36c1b0a6de51268fd3b9c714d91f3811482263e734e416ea
 F ext/rtree/rtree2.test 5f25b01acd03470067a2d52783b2eb0a50bf836803d4342d20ca39e541220fe2
@@ -1807,7 +1807,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P d5acf3af65f9608d4096b9b78289d84b21cd1ea463457f858ffeb20d5bd5d123
-R f00f2011633eed78de2ba493a3b1eac3
+P 55be6d0a9fa8a64b9c9c5ed51a2b9144304f7f0870a13b92d5864ac4d54491b6
+R 115ebe89ec824cbf47067b926d59573e
 U drh
-Z 1def333ee1f2c7ed9dc916a2f0ad220f
+Z 07d1c7d0324b01226c5f702e4b24bb20
diff --git a/manifest.uuid b/manifest.uuid
index 07b1a6aaa5..0c98b34b44 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-55be6d0a9fa8a64b9c9c5ed51a2b9144304f7f0870a13b92d5864ac4d54491b6
\ No newline at end of file
+90acdbfce9c088582d5165589f7eac462b00062bbfffacdcc786eb9cf3ea5377
\ No newline at end of file