From 3f3db5422397f1bf8d5af1ade256638d89b1081c Mon Sep 17 00:00:00 2001
From: Robin Haberkorn <rhaberkorn@fmsbw.de>
Date: Sun, 23 Aug 2026 21:51:48 +0200
Subject: functions that can tail-call must be tail-called as well

Otherwise we could "leak" stack frames, which causes crashes on platforms with small stack sizes.
This still did not result in a reproducable speedup with GCC 16.

fixup 2e097cec409182c3cb39b74489387480bf8a278f
---
 src/core-commands.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

(limited to 'src/core-commands.c')

diff --git a/src/core-commands.c b/src/core-commands.c
index d01cbb9..d850c14 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -914,10 +914,8 @@ teco_state_start_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 		/*
 		 * <CTRL/x> commands implemented in teco_state_control
 		 */
-		if (TECO_IS_CTL(chr)) {
-			teco_state_t *next = teco_state_control_input(ctx, TECO_CTL_ECHO(chr), error);
-			TECO_RETURN(ctx, next, error);
-		}
+		if (TECO_IS_CTL(chr))
+			TECO_TAIL return teco_state_control_input(ctx, TECO_CTL_ECHO(chr), error);
 	}
 
 	teco_state_t *next = teco_machine_main_transition_input(ctx, transitions, G_N_ELEMENTS(transitions),
@@ -1828,7 +1826,7 @@ TECO_DEFINE_STATE(teco_state_ascii,
  * at the expense of yet another parser state.
  */
 static teco_state_t *
-teco_return(teco_machine_main_t *ctx, GError **error)
+teco_throw_return(teco_machine_main_t *ctx, GError **error)
 {
 	g_assert(ctx->flags.mode == TECO_MODE_NORMAL);
 
@@ -1871,9 +1869,11 @@ teco_return(teco_machine_main_t *ctx, GError **error)
 static teco_state_t *
 teco_state_escape_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 {
-	if (chr == '\e' || chr == '$')
-		return ctx->flags.mode > TECO_MODE_NORMAL
-			? &teco_state_start : teco_return(ctx, error);
+	if (chr == '\e' || chr == '$') {
+		if (ctx->flags.mode > TECO_MODE_NORMAL)
+			TECO_RETURN(ctx, &teco_state_start, error);
+		return teco_throw_return(ctx, error);
+	}
 
 	/*
 	 * Alternatives: ^[, <CTRL/[>, <ESC>, $ (dollar)
@@ -1900,7 +1900,7 @@ teco_state_escape_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 	if (ctx->flags.mode == TECO_MODE_NORMAL &&
 	    !teco_expressions_discard_args(error))
 		return NULL;
-	return teco_state_start_input(ctx, chr, error);
+	TECO_TAIL return teco_state_start_input(ctx, chr, error);
 }
 
 static gboolean
@@ -1940,12 +1940,13 @@ static teco_state_t *
 teco_state_ctlc_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 {
 	switch (chr) {
-	case TECO_CTL_KEY('C'):	return teco_state_ctlc_control_input(ctx, 'C', error);
+	case TECO_CTL_KEY('C'):	TECO_TAIL return teco_state_ctlc_control_input(ctx, 'C', error);
 	case '^':		TECO_RETURN(ctx, &teco_state_ctlc_control, error);
 	}
 
-	return ctx->flags.mode > TECO_MODE_NORMAL
-		? teco_state_start_input(ctx, chr, error) : teco_return(ctx, error);
+	if (ctx->flags.mode > TECO_MODE_NORMAL)
+		TECO_TAIL return teco_state_start_input(ctx, chr, error);
+	return teco_throw_return(ctx, error);
 }
 
 static gboolean
@@ -2009,8 +2010,9 @@ teco_state_ctlc_control_input(teco_machine_main_t *ctx, gunichar chr, GError **e
 		return NULL;
 	}
 
-	return ctx->flags.mode > TECO_MODE_NORMAL
-		? teco_state_control_input(ctx, chr, error) : teco_return(ctx, error);
+	if (ctx->flags.mode > TECO_MODE_NORMAL)
+		TECO_TAIL return teco_state_control_input(ctx, chr, error);
+	return teco_throw_return(ctx, error);
 }
 
 /*
-- 
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