From dcd7360b174fa79487594257e5e965d707cceb4c Mon Sep 17 00:00:00 2001
From: Mark <markjordanthom@gmail.com>
Date: Thu, 20 Jul 2023 09:39:06 -0600
Subject: [PATCH] add EMIT_NEWLINE to add newlines to readline input only after
 query terms begin to be read (#1074, #1897)

---
 src/machine/system_calls.rs |  1 +
 src/read.rs                 | 15 ++++++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/machine/system_calls.rs b/src/machine/system_calls.rs
index 0d4b5e92..f9969669 100644
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -5797,6 +5797,7 @@ impl Machine {
     pub(crate) fn read_query_term(&mut self) -> CallResult {
         self.user_input.reset();
 
+        set_emit_newline(true);
         set_prompt(true);
         // let result = self.machine_st.read_term(self.user_input, &mut self.indices);
         let result = self.machine_st.read_term_from_user_input(self.user_input, &mut self.indices);
diff --git a/src/read.rs b/src/read.rs
index 3afb4bf9..c21c3016 100644
--- a/src/read.rs
+++ b/src/read.rs
@@ -80,9 +80,16 @@ impl MachineState {
 }
 
 static mut PROMPT: bool = false;
+static mut EMIT_NEWLINE: bool = false;
 
 const HISTORY_FILE: &'static str = ".scryer_history";
 
+pub(crate) fn set_emit_newline(value: bool) {
+    unsafe {
+        EMIT_NEWLINE = value;
+    }
+}
+
 pub(crate) fn set_prompt(value: bool) {
     unsafe {
         PROMPT = value;
@@ -161,10 +168,12 @@ impl ReadlineStream {
                         self.save_history();
                         PROMPT = false;
                     }
-                }
 
-                if self.pending_input.get_ref().get_ref().chars().last() != Some('\n') {
-                    *self.pending_input.get_mut().get_mut() += "\n";
+                    if EMIT_NEWLINE {
+                        if self.pending_input.get_ref().get_ref().chars().last() != Some('\n') {
+                            *self.pending_input.get_mut().get_mut() += "\n";
+                        }
+                    }
                 }
 
                 Ok(self.pending_input.get_ref().get_ref().len())
-- 
2.54.0