fix: Fix append regression in 0.13.5

prqlc/prqlc/src/sql/pq/positional_mapping.rs

@@ -28,6 +28,16 @@ impl PositionalMapper {
     /// Reorder or remove columns to make `Union` happy.
     pub(crate) fn apply_active_mapping(&mut self, output: Vec<CId>) -> Vec<CId> {
         if let Some(mapping) = &self.active_positional_mapping {
+            // Check if the mapping indices are valid for the output
+            if mapping.iter().any(|idx| *idx >= output.len()) {
+                log::warn!(
+                    "positional mapping indices out of bounds: mapping={mapping:?}, output_len={}",
+                    output.len()
+                );
+                // If mapping is invalid, don't apply it
+                return output;
+            }
+
             let new_output = mapping.iter().map(|idx| output[*idx]).collect();
             log::debug!("remapping {output:?} to {new_output:?} via {mapping:?}");
             new_output
@@ -48,9 +58,18 @@ impl PositionalMapper {
             })
             .collect();
 
-        if !self.relation_positional_mapping.contains_key(riid) {
+        // Only store the mapping if it's complete (all columns matched)
+        // If mapping is incomplete, it means the bottom relation hasn't been fully
+        // compiled yet, so we shouldn't apply any mapping
+        if mapping.len() == after.len() && !self.relation_positional_mapping.contains_key(riid) {
             log::debug!(".. relation {riid:?} will be mapped: {mapping:?}");
             self.relation_positional_mapping.insert(*riid, mapping);
+        } else if mapping.len() != after.len() {
+            log::debug!(
+                ".. skipping incomplete mapping for {riid:?}: {}/{} columns matched",
+                mapping.len(),
+                after.len()
+            );
         }
     }
 }

prqlc/prqlc/tests/integration/queries/append_cte_complex.prql

@@ -0,0 +1,26 @@
+prql target:sql.postgres
+
+let invoices_wrap = (
+  from invoices
+  select { invoice_id, billing_country }
+)
+
+let employees_wrap = (
+  from employees
+  select { employee_id, country }
+)
+
+let invoices_final = (
+  from invoices_wrap
+  select { invoice_id, billing_country }
+  derive { source = f"{billing_country} from invoices" }
+)
+
+let employees_final = (
+  from employees_wrap
+  select { employee_id, country }
+  derive { source = f"{country} from employees" }
+)
+
+from invoices_final
+append employees_final

prqlc/prqlc/tests/integration/snapshots/integration__queries__compile__append_cte_complex.snap

@@ -0,0 +1,42 @@
+---
+source: prqlc/prqlc/tests/integration/queries.rs
+expression: "prql target:sql.postgres\n\nlet invoices_wrap = (\n  from invoices\n  select { invoice_id, billing_country }\n)\n\nlet employees_wrap = (\n  from employees\n  select { employee_id, country }\n)\n\nlet invoices_final = (\n  from invoices_wrap\n  select { invoice_id, billing_country }\n  derive { source = f\"{billing_country} from invoices\" }\n)\n\nlet employees_final = (\n  from employees_wrap\n  select { employee_id, country }\n  derive { source = f\"{country} from employees\" }\n)\n\nfrom invoices_final\nappend employees_final\n"
+input_file: prqlc/prqlc/tests/integration/queries/append_cte_complex.prql
+snapshot_kind: text
+---
+WITH invoices_wrap AS (
+  SELECT
+    invoice_id,
+    billing_country
+  FROM
+    invoices
+),
+invoices_final AS (
+  SELECT
+    invoice_id,
+    billing_country,
+    CONCAT(billing_country, ' from invoices') AS source
+  FROM
+    invoices_wrap
+),
+employees_wrap AS (
+  SELECT
+    employee_id,
+    country
+  FROM
+    employees
+)
+SELECT
+  invoice_id,
+  billing_country,
+  source
+FROM
+  invoices_final
+UNION
+ALL
+SELECT
+  employee_id,
+  country,
+  CONCAT(country, ' from employees') AS source
+FROM
+  employees_wrap

prqlc/prqlc/tests/integration/snapshots/integration__queries__compile__append_select.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nselect { customer_id, invoice_id, billing_country }\ntake 10..15\nappend (\n  from invoices\n  select { customer_id, invoice_id, billing_country }\n  take 40..45\n)\nselect { billing_country, invoice_id }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select.prql
+snapshot_kind: text
 ---
 SELECT
   *

prqlc/prqlc/tests/integration/snapshots/integration__queries__compile__append_select_compute.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nderive total = case [total < 10 => total * 2, true => total]\nselect { customer_id, invoice_id, total }\ntake 5\nappend (\n  from invoice_items\n  derive unit_price = case [unit_price < 1 => unit_price * 2, true => unit_price]\n  select { invoice_line_id, invoice_id, unit_price }\n  take 5\n)\nselect { a = customer_id * 2, b = math.round 1 (invoice_id * total) }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select_compute.prql
+snapshot_kind: text
 ---
 WITH table_1 AS (
   SELECT

prqlc/prqlc/tests/integration/snapshots/integration__queries__compile__append_select_multiple_with_null.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nselect { customer_id, invoice_id, billing_country }\ntake 5\nappend (\n  from employees\n  select { employee_id, employee_id, country }\n  take 5\n)\nappend (\n  from invoice_items\n  select { invoice_line_id, invoice_id, null }\n  take 5\n)\nselect { billing_country, invoice_id }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select_multiple_with_null.prql
+snapshot_kind: text
 ---
 SELECT
   *

prqlc/prqlc/tests/integration/snapshots/integration__queries__compileall__append_cte_complex.snap

@@ -0,0 +1,46 @@
+---
+source: prqlc/prqlc/tests/integration/queries.rs
+expression: "prql target:sql.postgres\n\nlet invoices_wrap = (\n  from invoices\n  select { invoice_id, billing_country }\n)\n\nlet employees_wrap = (\n  from employees\n  select { employee_id, country }\n)\n\nlet invoices_final = (\n  from invoices_wrap\n  select { invoice_id, billing_country }\n  derive { source = f\"{billing_country} from invoices\" }\n)\n\nlet employees_final = (\n  from employees_wrap\n  select { employee_id, country }\n  derive { source = f\"{country} from employees\" }\n)\n\nfrom invoices_final\nappend employees_final\n"
+input_file: prqlc/prqlc/tests/integration/queries/append_cte_complex.prql
+snapshot_kind: text
+---
+--- generic
++++ sqlite
+@@ -2,21 +2,21 @@
+   SELECT
+     invoice_id,
+     billing_country
+   FROM
+     invoices
+ ),
+ invoices_final AS (
+   SELECT
+     invoice_id,
+     billing_country,
+-    CONCAT(billing_country, ' from invoices') AS source
++    billing_country || ' from invoices' AS source
+   FROM
+     invoices_wrap
+ ),
+ employees_wrap AS (
+   SELECT
+     employee_id,
+     country
+   FROM
+     employees
+ )
+@@ -24,13 +24,13 @@
+   invoice_id,
+   billing_country,
+   source
+ FROM
+   invoices_final
+ UNION
+ ALL
+ SELECT
+   employee_id,
+   country,
+-  CONCAT(country, ' from employees') AS source
++  country || ' from employees' AS source
+ FROM
+   employees_wrap

prqlc/prqlc/tests/integration/snapshots/integration__queries__compileall__append_select.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nselect { customer_id, invoice_id, billing_country }\ntake 10..15\nappend (\n  from invoices\n  select { customer_id, invoice_id, billing_country }\n  take 40..45\n)\nselect { billing_country, invoice_id }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select.prql
+snapshot_kind: text
 ---
 --- generic
 +++ postgres

prqlc/prqlc/tests/integration/snapshots/integration__queries__compileall__append_select_compute.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nderive total = case [total < 10 => total * 2, true => total]\nselect { customer_id, invoice_id, total }\ntake 5\nappend (\n  from invoice_items\n  derive unit_price = case [unit_price < 1 => unit_price * 2, true => unit_price]\n  select { invoice_line_id, invoice_id, unit_price }\n  take 5\n)\nselect { a = customer_id * 2, b = math.round 1 (invoice_id * total) }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select_compute.prql
+snapshot_kind: text
 ---
 --- generic
 +++ glaredb

prqlc/prqlc/tests/integration/snapshots/integration__queries__compileall__append_select_multiple_with_null.snap

@@ -2,6 +2,7 @@
 source: prqlc/prqlc/tests/integration/queries.rs
 expression: "from invoices\nselect { customer_id, invoice_id, billing_country }\ntake 5\nappend (\n  from employees\n  select { employee_id, employee_id, country }\n  take 5\n)\nappend (\n  from invoice_items\n  select { invoice_line_id, invoice_id, null }\n  take 5\n)\nselect { billing_country, invoice_id }\n"
 input_file: prqlc/prqlc/tests/integration/queries/append_select_multiple_with_null.prql
+snapshot_kind: text
 ---
 --- generic
 +++ postgres