rhg: [encode] and [decode] config sections are not supported

Differential Revision: https://phab.mercurial-scm.org/D11761

rust/hg-core/src/config/config.rs

@@ -403,6 +403,13 b' impl Config {'
             .collect()
     }
 
+    /// Returns whether any key is defined in the given section
+    pub fn has_non_empty_section(&self, section: &[u8]) -> bool {
+        self.layers
+            .iter()
+            .any(|layer| layer.has_non_empty_section(section))
+    }
+
     /// Get raw values bytes from all layers (even untrusted ones) in order
     /// of precedence.
     #[cfg(test)]

rust/hg-core/src/config/layer.rs

@@ -127,6 +127,13 b' impl ConfigLayer {'
             .flat_map(|section| section.keys().map(|vec| &**vec))
     }
 
+    /// Returns whether any key is defined in the given section
+    pub fn has_non_empty_section(&self, section: &[u8]) -> bool {
+        self.sections
+            .get(section)
+            .map_or(false, |section| !section.is_empty())
+    }
+
     pub fn is_empty(&self) -> bool {
         self.sections.is_empty()
     }

rust/rhg/src/main.rs

@@ -626,5 +626,13 b' fn check_unsupported(config: &Config) ->'
         Err(CommandError::unsupported("$HG_PENDING"))?
     }
 
+    if config.has_non_empty_section(b"encode") {
+        Err(CommandError::unsupported("[encode] config"))?
+    }
+
+    if config.has_non_empty_section(b"decode") {
+        Err(CommandError::unsupported("[decode] config"))?
+    }
+
     Ok(())
 }

tests/test-encode.t

@@ -1,7 +1,3 b''
-TODO: fix rhg bugs that make this test fail when status is enabled
-  $ unset RHG_STATUS
-
-
 Test encode/decode filters
 
   $ hg init