Add Runtime::input_is_pipe()

We need this because we might want to check whether we can get the STDIN
handle from the runtime or not.
In some (rare) cases, the runtime "thinks" that STDIN is a stream of
IDs, but it is not. So the client can check whether stdin is a pipe
(thus, whether Runtime thinks that there's a stream of IDs) and easily
work around that by taking ::std::io::stdin() itself.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

lib/core/libimagrt/src/runtime.rs

@@ -336,10 +336,6 @@ impl<'a> Runtime<'a> {
         &self.cli_matches
     }
 
-    pub fn ids_from_stdin(&self) -> bool {
-        self.has_input_pipe
-    }
-
     pub fn ids<T: IdPathProvider>(&self) -> Result<Option<Vec<StoreId>>> {
         use std::io::Read;
 
@@ -410,6 +406,16 @@ impl<'a> Runtime<'a> {
         self.has_output_pipe
     }
 
+    pub fn input_is_pipe(&self) -> bool {
+        self.has_input_pipe
+    }
+
+    /// Alias for Runtime::input_is_pipe()
+    pub fn ids_from_stdin(&self) -> bool {
+        self.input_is_pipe()
+    }
+
+
     /// Check whether the runtime ignores touched ids
     ///
     /// "Ignoring" in this context means whether the runtime prints them or not.