imDefLkup: Commit first info in XimCommitInfo

Xic.private.proto.commit_info can receive multiple XimCommitInfo
when typing keys very quickly like an bar code scanner (or evemu-play)
and the first info in XimCommitInfo should be committed to keep
the typing key order.

This and 041b5291 are same patches but the regression issues will be
fixed by the later patches.

Closes: #198
Fixes: 041b5291 ("imDefLkup: Commit first info in XimCommitInfo")
Part-of: <https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/246>

1 files changed, 49 insertions, 11 deletions

diff --git a/modules/im/ximcp/imDefLkup.c b/modules/im/ximcp/imDefLkup.c
index 5192e8c1..6ffe6f48 100644
--- a/modules/im/ximcp/imDefLkup.c
+++ b/modules/im/ximcp/imDefLkup.c
@@ -640,22 +640,47 @@ _XimRegCommitInfo(
 }
 
 static void
-_XimUnregCommitInfo(
-    Xic			ic)
+_XimUnregRealCommitInfo(
+    Xic			ic,
+    Bool		reverse)
 {
     XimCommitInfo	info;
+    XimCommitInfo	prev_info = NULL;
 
-    if (!(info = ic->private.proto.commit_info))
+    info = ic->private.proto.commit_info;
+    while (reverse && info) {
+	if (!info->next)
+	    break;
+	prev_info = info;
+	info = info->next;
+    }
+    if (!info)
 	return;
 
-
     Xfree(info->string);
     Xfree(info->keysym);
-    ic->private.proto.commit_info = info->next;
+    if (prev_info)
+	prev_info->next = info->next;
+    else
+	ic->private.proto.commit_info = info->next;
     Xfree(info);
     return;
 }
 
+static void
+_XimUnregCommitInfo(
+    Xic			ic)
+{
+    _XimUnregRealCommitInfo(ic, False);
+}
+
+static void
+_XimUnregFirstCommitInfo(
+    Xic			ic)
+{
+    _XimUnregRealCommitInfo(ic, True);
+}
+
 void
 _XimFreeCommitInfo(
     Xic			ic)
@@ -665,6 +690,19 @@ _XimFreeCommitInfo(
     return;
 }
 
+static XimCommitInfo
+_XimFirstCommitInfo(
+    Xic			ic)
+{
+    XimCommitInfo info = ic->private.proto.commit_info;
+    while (info) {
+	if (!info->next)
+	    break;
+	info = info->next;
+    }
+    return info;
+}
+
 static Bool
 _XimProcKeySym(
     Xic			  ic,
@@ -1059,7 +1097,7 @@ _XimProtoMbLookupString(
 	state = &tmp_state;
 
     if ((ev->type == KeyPress) && (ev->keycode == 0)) { /* Filter function */
-	if (!(info = ic->private.proto.commit_info)) {
+	if (!(info = _XimFirstCommitInfo(ic))) {
 	    *state = XLookupNone;
 	    return 0;
 	}
@@ -1075,7 +1113,7 @@ _XimProtoMbLookupString(
 	    else
 		*state = XLookupKeySym;
 	}
-	_XimUnregCommitInfo(ic);
+	_XimUnregFirstCommitInfo(ic);
 
     } else  if (ev->type == KeyPress) {
 	ret = _XimLookupMBText(ic, ev, buffer, bytes, keysym, NULL);
@@ -1122,7 +1160,7 @@ _XimProtoWcLookupString(
 	state = &tmp_state;
 
     if (ev->type == KeyPress && ev->keycode == 0) { /* Filter function */
-	if (!(info = ic->private.proto.commit_info)) {
+	if (!(info = _XimFirstCommitInfo(ic))) {
            *state = XLookupNone;
 	    return 0;
 	}
@@ -1138,7 +1176,7 @@ _XimProtoWcLookupString(
 	    else
 		*state = XLookupKeySym;
 	}
-	_XimUnregCommitInfo(ic);
+	_XimUnregFirstCommitInfo(ic);
 
     } else if (ev->type == KeyPress) {
 	ret = _XimLookupWCText(ic, ev, buffer, bytes, keysym, NULL);
@@ -1185,7 +1223,7 @@ _XimProtoUtf8LookupString(
 	state = &tmp_state;
 
     if (ev->type == KeyPress && ev->keycode == 0) { /* Filter function */
-	if (!(info = ic->private.proto.commit_info)) {
+	if (!(info = _XimFirstCommitInfo(ic))) {
            *state = XLookupNone;
 	    return 0;
 	}
@@ -1201,7 +1239,7 @@ _XimProtoUtf8LookupString(
 	    else
 		*state = XLookupKeySym;
 	}
-	_XimUnregCommitInfo(ic);
+	_XimUnregFirstCommitInfo(ic);
 
     } else if (ev->type == KeyPress) {
 	ret = _XimLookupUTF8Text(ic, ev, buffer, bytes, keysym, NULL);