[pbs-devel] [PATCH proxmox 2/2] section config: fix handling array schema in unknown sections

[Fiona Ebner <f.ebner@proxmox.com>]

Mostly relevant when the config is written out again after parsing it
with unknown sections. Previously, with duplicate keys, only the last
value would be saved. Now, duplicate keys are assumed to be part of
an array schema and handled as such.

Because the unknown section parsing does not know if a certain
property does actually have an array schema, it's not possible to
detect duplicate keys for non-array-schema properties, and if a
property with array-schema shows up only once, it will not be saved as
a Value::Array, but a Value::String.

Writing, or to be precise the format_section_content methods, already
handle Value::Array, so don't need to be adapted.

Fixes: 0cd0d16 ("section config: support allowing unknown section types")
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
 proxmox-section-config/src/lib.rs | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/proxmox-section-config/src/lib.rs b/proxmox-section-config/src/lib.rs
index 929ab92..66eeacf 100644
--- a/proxmox-section-config/src/lib.rs
+++ b/proxmox-section-config/src/lib.rs
@@ -529,7 +529,14 @@ impl SectionConfig {
                                 continue;
                             }
                             if let Some((key, value)) = (self.parse_section_content)(line) {
-                                config[key] = json!(value);
+                                match &mut config[&key] {
+                                    Value::Null => config[key] = json!(value),
+                                    // Assume it's an array schema in order to handle actual array
+                                    // schemas as good as we can.
+                                    Value::String(current) => config[key] = json!([current, value]),
+                                    Value::Array(array) => array.push(json!(value)),
+                                    other => bail!("got unexpected Value {:?}", other),
+                                }
                             } else {
                                 bail!("syntax error (expected section properties)");
                             }
@@ -1137,6 +1144,8 @@ fn test_section_config_array() {
     let mut config = SectionConfig::new(&ID_SCHEMA);
     config.register_plugin(plugin);
 
+    let config_unknown = SectionConfig::new(&ID_SCHEMA).allow_unknown_sections(true);
+
     let raw = r"
 
 sync: s-4a1011e8-40e2
@@ -1182,6 +1191,15 @@ sync: s-6c32330a-6204
 
     check(res);
 
+    let res_unknown = config_unknown.parse(filename, raw).unwrap();
+    println!("RES (unknown): {:?}", res_unknown);
+    let written_unknown = config_unknown.write(filename, &res_unknown).unwrap();
+    println!("CONFIG (unknown):\n{}", written_unknown);
+
+    check(res_unknown);
+
+    assert_eq!(written, written_unknown);
+
     let raw = r"
 
 sync: fail
-- 
2.30.2