Disable negative offsets for SETRANGE

src/t_string.c

@@ -195,11 +195,13 @@ void setrangeCommand(redisClient *c) {
     if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != REDIS_OK)
         return;
 
+    if (offset < 0) {
+        addReplyError(c,"offset is out of range");
+        return;
+    }
+
     o = lookupKeyWrite(c->db,c->argv[1]);
     if (o == NULL) {
-        /* Negative offset is always 0 for non-existing keys */
-        if (offset < 0) offset = 0;
-
         /* Return 0 when setting nothing on a non-existing string */
         if (sdslen(value) == 0) {
             addReply(c,shared.czero);
@@ -233,15 +235,6 @@ void setrangeCommand(redisClient *c) {
             return;
         }
 
-        /* Convert negative indexes. Note that for SETRANGE, the meaning of a
-         * negative index is a little different than for other commands.
-         * Here, an offset of -1 points to the trailing NULL byte of the
-         * string instead of the last character. */
-        if (offset < 0) {
-            offset = olen+1+offset;
-            if (offset < 0) offset = 0;
-        }
-
         /* Return when the resulting string exceeds allowed size */
         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
             return;

tests/unit/basic.tcl

@@ -489,14 +489,6 @@ start_server {tags {"basic"}} {
         r del mykey
         assert_equal 4 [r setrange mykey 1 foo]
         assert_equal "\000foo" [r get mykey]
-
-        r del mykey
-        assert_equal 3 [r setrange mykey -1 foo]
-        assert_equal "foo" [r get mykey]
-
-        r del mykey
-        assert_equal 3 [r setrange mykey -100 foo]
-        assert_equal "foo" [r get mykey]
     }
 
     test "SETRANGE against string-encoded key" {
@@ -512,18 +504,6 @@ start_server {tags {"basic"}} {
         assert_equal 3 [r setrange mykey 1 b]
         assert_equal "fbo" [r get mykey]
 
-        r set mykey "foo"
-        assert_equal 6 [r setrange mykey -1 bar]
-        assert_equal "foobar" [r get mykey]
-
-        r set mykey "foo"
-        assert_equal 5 [r setrange mykey -2 bar]
-        assert_equal "fobar" [r get mykey]
-
-        r set mykey "foo"
-        assert_equal 3 [r setrange mykey -20 bar]
-        assert_equal "bar" [r get mykey]
-
         r set mykey "foo"
         assert_equal 7 [r setrange mykey 4 bar]
         assert_equal "foo\000bar" [r get mykey]
@@ -549,18 +529,6 @@ start_server {tags {"basic"}} {
         assert_encoding raw mykey
         assert_equal 1334 [r get mykey]
 
-        r set mykey 1234
-        assert_encoding int mykey
-        assert_equal 5 [r setrange mykey -1 5]
-        assert_encoding raw mykey
-        assert_equal 12345 [r get mykey]
-
-        r set mykey 1234
-        assert_encoding int mykey
-        assert_equal 4 [r setrange mykey -2 5]
-        assert_encoding raw mykey
-        assert_equal 1235 [r get mykey]
-
         r set mykey 1234
         assert_encoding int mykey
         assert_equal 6 [r setrange mykey 5 2]
@@ -577,7 +545,9 @@ start_server {tags {"basic"}} {
     test "SETRANGE with out of range offset" {
         r del mykey
         assert_error "*maximum allowed size*" {r setrange mykey [expr 512*1024*1024-4] world}
+
         r set mykey "hello"
+        assert_error "*out of range*" {r setrange mykey -1 world}
         assert_error "*maximum allowed size*" {r setrange mykey [expr 512*1024*1024-4] world}
     }