add tests and fix

Author: czeildi

R/data.table.R

@@ -1448,7 +1448,7 @@ replace_dot_alias = function(e) {
         if (SD_only)
           jvnames = jnames = sdvars
         else
-          jnames = as.character(Filter(is.name, jsub)[-1L])
+          jnames = vapply_1c(jsub, \(x) `if`(is.name(x), as.character(x), NA_character_))[-1L]
         key_idx = chmatch(key, jnames)
         missing_keys = which(is.na(key_idx))
         if (length(missing_keys) && missing_keys[1L] == 1L) return(NULL)

inst/tests/tests.Rraw

@@ -21837,3 +21837,29 @@ DT[, V1000 := 20:1]
 test(2343.1, forderv(DT, by=names(DT), sort=FALSE, retGrp=TRUE), forderv(DT, by=c("V1", "V1000"), sort=FALSE, retGrp=TRUE))
 x = c(rep(0, 7e5), 1e6)
 test(2343.2, forderv(list(x)), integer(0))
+
+# Keep key when new column added before existing key in j
+# Incorrect key can lead to incorrect join result #7364
+local({
+  test(2344.00, key(data.table(V1 = 1:2, key = "V1")[, .(V2 = c("b", "a"), V1)]), "V1")
+  test(2344.01, key(data.table(V1 = 1:2, key = "V1")[, .(V2 = -V1, V1)]), "V1")
+
+  d1 = data.table(
+    V1 = c(1L, 0L, 1L),
+    V2 = c("a", "a", "b"),
+    key = "V2"
+  )
+
+  d2 = d1[, .(
+    V1,
+    label = c("one", "zero", "one"),
+    V2
+  )]
+
+  r = d2[
+    data.table(label = "one"),
+    on = "label",
+    allow.cartesian = TRUE
+  ]
+  test(2344.02, nrow(r), 2L)
+})