From: Karl Heuer <kwzh@gnu.org>
Date: Tue, 17 Jan 1995 00:18:20 +0000 (+0000)
Subject: (cmcheckmagic): New function.
X-Git-Tag: emacs-19.34~5421
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=902a3b86a41b7142ba27c0430a9dff06e878fc14;p=emacs.git

(cmcheckmagic): New function.
---

diff --git a/src/cm.c b/src/cm.c
index f0ea1e26f1c..5d18e812e5a 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -99,6 +99,35 @@ addcol (n) {
 }
 #endif
 
+/*
+ * Terminals with magicwrap (xn) don't all behave identically.
+ * The VT100 leaves the cursor in the last column but will wrap before
+ * printing the next character.  I hear that the Concept terminal does
+ * the wrap immediately but ignores the next newline it sees.  And some
+ * terminals just have buggy firmware, and think that the cursor is still
+ * in limbo if we use direct cursor addressing from the phantom column.
+ * The only guaranteed safe thing to do is to emit a CRLF immediately
+ * after we reach the last column; this takes us to a known state.
+ */
+void
+cmcheckmagic ()
+{
+  if (curX == FrameCols)
+    {
+      if (!MagicWrap || curY >= FrameRows - 1)
+	abort ();
+      if (termscript)
+	putc ('\r', termscript);
+      putchar ('\r');
+      if (termscript)
+	putc ('\n', termscript);
+      putchar ('\n');
+      curX = 0;
+      curY++;
+    }
+}
+
+
 /*
  * (Re)Initialize the cost factors, given the output speed of the terminal
  * in the variable ospeed.  (Note: this holds B300, B9600, etc -- ie stuff