rpc: return err if page is incorrect (less than 0 or greater than tot… (#3825)

* rpc: return err if page is incorrect (less than 0 or greater than total pages)

Fixes #3813

* fix rpc_test

CHANGELOG_PENDING.md

@@ -27,3 +27,5 @@ program](https://hackerone.com/tendermint).
 - [mempool] \#3826 Make `max_msg_bytes` configurable
 
 ### BUG FIXES:
+
+- [rpc] \#3813 Return err if page is incorrect (less than 0 or greater than total pages)

rpc/core/pipe.go

@@ -1,6 +1,7 @@
 package core
 
 import (
+	"fmt"
 	"time"
 
 	cfg "github.com/tendermint/tendermint/config"
@@ -145,19 +146,24 @@ func SetConfig(c cfg.RPCConfig) {
 	config = c
 }
 
-func validatePage(page, perPage, totalCount int) int {
+func validatePage(page, perPage, totalCount int) (int, error) {
 	if perPage < 1 {
-		return 1
+		panic(fmt.Sprintf("zero or negative perPage: %d", perPage))
+	}
+
+	if page == 0 {
+		return 1, nil // default
 	}
 
 	pages := ((totalCount - 1) / perPage) + 1
-	if page < 1 {
-		page = 1
-	} else if page > pages {
-		page = pages
+	if pages == 0 {
+		pages = 1 // one page (even if it's empty)
+	}
+	if page < 0 || page > pages {
+		return 1, fmt.Errorf("page should be within [0, %d] range, given %d", pages, page)
 	}
 
-	return page
+	return page, nil
 }
 
 func validatePerPage(perPage int) int {

rpc/core/pipe_test.go

@@ -14,33 +14,39 @@ func TestPaginationPage(t *testing.T) {
 		perPage    int
 		page       int
 		newPage    int
+		expErr     bool
 	}{
-		{0, 0, 1, 1},
+		{0, 10, 1, 1, false},
 
-		{0, 10, 0, 1},
-		{0, 10, 1, 1},
-		{0, 10, 2, 1},
+		{0, 10, 0, 1, false},
+		{0, 10, 1, 1, false},
+		{0, 10, 2, 0, true},
 
-		{5, 10, -1, 1},
-		{5, 10, 0, 1},
-		{5, 10, 1, 1},
-		{5, 10, 2, 1},
-		{5, 10, 2, 1},
+		{5, 10, -1, 0, true},
+		{5, 10, 0, 1, false},
+		{5, 10, 1, 1, false},
+		{5, 10, 2, 0, true},
+		{5, 10, 2, 0, true},
 
-		{5, 5, 1, 1},
-		{5, 5, 2, 1},
-		{5, 5, 3, 1},
+		{5, 5, 1, 1, false},
+		{5, 5, 2, 0, true},
+		{5, 5, 3, 0, true},
 
-		{5, 3, 2, 2},
-		{5, 3, 3, 2},
+		{5, 3, 2, 2, false},
+		{5, 3, 3, 0, true},
 
-		{5, 2, 2, 2},
-		{5, 2, 3, 3},
-		{5, 2, 4, 3},
+		{5, 2, 2, 2, false},
+		{5, 2, 3, 3, false},
+		{5, 2, 4, 0, true},
 	}
 
 	for _, c := range cases {
-		p := validatePage(c.page, c.perPage, c.totalCount)
+		p, err := validatePage(c.page, c.perPage, c.totalCount)
+		if c.expErr {
+			assert.Error(t, err)
+			continue
+		}
+
 		assert.Equal(t, c.newPage, p, fmt.Sprintf("%v", c))
 	}
 

rpc/core/tx.go

@@ -202,7 +202,10 @@ func TxSearch(ctx *rpctypes.Context, query string, prove bool, page, perPage int
 
 	totalCount := len(results)
 	perPage = validatePerPage(perPage)
-	page = validatePage(page, perPage, totalCount)
+	page, err = validatePage(page, perPage, totalCount)
+	if err != nil {
+		return nil, err
+	}
 	skipCount := validateSkipCount(page, perPage)
 
 	apiResults := make([]*ctypes.ResultTx, cmn.MinInt(perPage, totalCount-skipCount))