From de02ceed917f37eb13e2b240c28ef04c668ef2b2 Mon Sep 17 00:00:00 2001
From: nick black <dankamongmen@gmail.com>
Date: Fri, 7 Jan 2022 22:10:53 -0500
Subject: [PATCH] [load_ncinput] always capitalize ASCII when Ctrl is used

---
 doc/man/man3/notcurses_input.3.md | 18 +++++++++---------
 src/lib/in.c                      | 19 +++++++++++++++----
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/doc/man/man3/notcurses_input.3.md b/doc/man/man3/notcurses_input.3.md
index adec1743e..7c2955f60 100644
--- a/doc/man/man3/notcurses_input.3.md
+++ b/doc/man/man3/notcurses_input.3.md
@@ -207,17 +207,17 @@ In API4, the various **bool** modifier fields will go away, and these statuses
 will be merged into the ***modifiers*** bitmask. You are encouraged to use
 **ncinput_shift_p** and friends to future-proof your code.
 
-When support is detected, the Kitty keyboard disambiguation protocol will be
-requested. This eliminates most of the **BUGS** mentioned below.
-
 # BUGS
 
-The Shift key is not indicated in conjunction with typical Unicode text.
-If e.g. Shift is used to generate a capital letter 'A', ***id*** will equal 'A',
-and ***shift*** will be **false**. Similarly, when Ctrl is pressed along with a
-letter, the letter will currently always be reported in its uppercase form.
-E.g., if Shift, Ctrl, and 'a' are all pressed, this is indistinguishable from
-Ctrl and 'A'.
+Notcurses attempts to use the XTMODKEYS and Kitty keyboard disambiguation
+protocols. When supported, they eliminate most of these issues.
+
+The Shift key is traditionally not indicated in conjunction with typical
+Unicode text. If e.g. Shift is used to generate a capital letter 'A', ***id***
+will equal 'A', and ***shift*** will be **false**. Similarly, when Ctrl is
+pressed along with a letter, the letter will currently always be reported in
+its uppercase form. E.g., if Shift, Ctrl, and 'a' are all pressed, this is
+indistinguishable from Ctrl and 'A'.
 
 Ctrl pressed along with 'J' or 'M', whether Shift is pressed or not,
 currently registers as **NCKEY_ENTER**. This will likely change in the
diff --git a/src/lib/in.c b/src/lib/in.c
index 41481e50e..2e2a9d187 100644
--- a/src/lib/in.c
+++ b/src/lib/in.c
@@ -476,16 +476,27 @@ mark_pipe_ready(ipipe pipes[static 2]){
   }
 }
 
-// shove the assembled input |tni| into the input queue (if there's room,
-// and we're not draining, and we haven't hit EOF). send any synthesized
-// signal as the last thing we do.
+// shove the assembled input |tni| into the input queue (if there's room, and
+// we're not draining, and we haven't hit EOF). send any synthesized signal as
+// the last thing we do. if Ctrl is among the modifiers, we replace any
+// lowercase letter with its uppercase form, to maintain compatibility with
+// other input methods.
 static void
-load_ncinput(inputctx* ictx, const ncinput *tni, int synthsig){
+load_ncinput(inputctx* ictx, ncinput *tni, int synthsig){
   inc_input_events(ictx);
   if(ictx->drain || ictx->stdineof){
     send_synth_signal(synthsig);
     return;
   }
+  if(tni->modifiers & NCKEY_MOD_CTRL){
+    // when ctrl is used with an ASCII (0..127) lowercase letter, we always
+    // supply the capitalized form, to maintain compatibility among solutions
+    if(tni->id < 0x7f){
+      if(islower(tni->id)){
+        tni->id = toupper(tni->id);
+      }
+    }
+  }
   pthread_mutex_lock(&ictx->ilock);
   if(ictx->ivalid == ictx->isize){
     pthread_mutex_unlock(&ictx->ilock);