fix segfault with empty numrange during from_datum() (#1918)

An empty `numrange` such as `'[10.5, 10.5)'::numrange` would lead to a
segfault during a `Range<AnyNumeric>::from_datum()`.

This also hardcodes CI to `runs-on: ubuntu-22.04` due to the upgrade in
-latest (actions/runner-images#10636) that I
don't have the patience to work out today.

.github/workflows/package-test.yaml

@@ -2,9 +2,9 @@ name: verify package can build
 
 on:
   push:
-    branches: [develop]
+    branches: [ develop ]
   pull_request:
-    branches: [develop]
+    branches: [ develop ]
 
 env:
   CARGO_TERM_COLOR: always
@@ -14,7 +14,7 @@ env:
 
 jobs:
   ubuntu:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/runas.yml

@@ -2,17 +2,17 @@ name: cargo pgrx test --runas
 
 on:
   push:
-    branches: [develop]
+    branches: [ develop ]
   pull_request:
-    branches: [develop]
+    branches: [ develop ]
 
 env:
   CARGO_TERM_COLOR: always
   RUST_BACKTRACE: 1
 
 jobs:
   ubuntu:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/tests.yml

@@ -20,7 +20,7 @@ env:
 jobs:
   lintck:
     name: rustfmt, clippy, et al.
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     if: "!contains(github.event.head_commit.message, 'nogha')"
     env:
       RUSTC_WRAPPER: sccache
@@ -97,7 +97,7 @@ jobs:
   pgrx_tests:
     name: Linux tests & examples
     needs: lintck
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     if: "!contains(github.event.head_commit.message, 'nogha')"
     env:
       RUSTC_WRAPPER: sccache
@@ -363,7 +363,7 @@ jobs:
 
   cargo_pgrx_init:
     name: cargo pgrx init
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     if: "!contains(github.event.head_commit.message, 'nogha')"
     env:
       RUSTC_WRAPPER: sccache

.github/workflows/will-it-blend-develop.yml

@@ -15,7 +15,7 @@ env:
 jobs:
   distro_tests:
     name: Distro tests
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false # We want all of them to run, even if one fails
       matrix:
@@ -36,7 +36,7 @@ jobs:
 
   cargo_unlocked_tests:
     name: Cargo unlocked tests
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false # We want all of them to run, even if one fails
       matrix:

pgrx-tests/src/tests/range_tests.rs

@@ -141,6 +141,14 @@ mod tests {
         assert_eq!(matched, Ok(Some(true)));
     }
 
+    #[pg_test]
+    fn test_empty_anynumeric_range() {
+        let matched = Spi::get_one::<Range<AnyNumeric>>(
+            "SELECT accept_range_numeric('[10.5, 10.5)'::numrange)",
+        );
+        assert_eq!(matched, Ok(Some(Range::empty())));
+    }
+
     #[pg_test]
     fn test_accept_range_date() {
         let matched =

pgrx/src/datum/range.rs

@@ -348,18 +348,26 @@ where
                     &mut is_empty,
                 );
 
-                // SAFETY: The lower_bound/upper_bound RangeBound value's .val will be a valid Datum of the T type
-                // If the range is_empty or either bound is infinite then .val = (Datum) 0
-                let lower = RangeBound::from_pg(lower_bound);
-                let upper = RangeBound::from_pg(upper_bound);
+                let range = if is_empty {
+                    // empty ranges cannot go through `RangeBound::from_pg()` as the bound's `.val`
+                    // Datum will be zero, and for a pass-by-reference range type, that's an instant segfault
+                    Range::empty()
+                } else {
+                    // SAFETY: The lower_bound/upper_bound RangeBound value's .val will be a valid Datum of the T type
+                    // If the range is_empty or either bound is infinite then .val = (Datum) 0, which we handled above
+                    let lower = RangeBound::from_pg(lower_bound);
+                    let upper = RangeBound::from_pg(upper_bound);
+
+                    Range { inner: Some((lower, upper)) }
+                };
 
                 if !std::ptr::eq(ptr, range_type.cast()) {
                     // SAFETY: range_type was allocated by Postgres in the call to
                     // pg_detoast_datum above, so we know it's a valid pointer and needs to be freed
                     pg_sys::pfree(range_type.cast());
                 }
 
-                Some(Range { inner: if is_empty { None } else { Some((lower, upper)) } })
+                Some(range)
             }
         }
     }