TUI: fix processing of bg color response

Terminal responses may be fragmented. In that case, the problem that was
not processed normally and was processed in the same way as user input
is corrected.

fixes #11393.

1 files changed, 27 insertions, 12 deletions

diff --git a/src/nvim/tui/input.c b/src/nvim/tui/input.c
index 62e0858301..2c9c8b78f3 100644
--- a/src/nvim/tui/input.c
+++ b/src/nvim/tui/input.c
@@ -462,39 +462,47 @@ static void set_bg_deferred(void **argv)
 // ignored in the calculations.
 //
 // [1] https://en.wikipedia.org/wiki/Luma_%28video%29
-static bool handle_background_color(TermInput *input)
+static HandleState handle_background_color(TermInput *input)
 {
   if (input->waiting_for_bg_response <= 0) {
-    return false;
+    return kNotApplicable;
   }
   size_t count = 0;
   size_t component = 0;
   size_t header_size = 0;
   size_t num_components = 0;
+  size_t buf_size = rbuffer_size(input->read_stream.buffer);
   uint16_t rgb[] = { 0, 0, 0 };
   uint16_t rgb_max[] = { 0, 0, 0 };
   bool eat_backslash = false;
   bool done = false;
   bool bad = false;
-  if (rbuffer_size(input->read_stream.buffer) >= 9
+  if (buf_size >= 9
       && !rbuffer_cmp(input->read_stream.buffer, "\x1b]11;rgb:", 9)) {
     header_size = 9;
     num_components = 3;
-  } else if (rbuffer_size(input->read_stream.buffer) >= 10
+  } else if (buf_size >= 10
              && !rbuffer_cmp(input->read_stream.buffer, "\x1b]11;rgba:", 10)) {
     header_size = 10;
     num_components = 4;
+  } else if (buf_size < 10
+             && !rbuffer_cmp(input->read_stream.buffer,
+                             "\x1b]11;rgba", buf_size)) {
+    // An incomplete sequence was found, waiting for the next input.
+    return kIncomplete;
   } else {
     input->waiting_for_bg_response--;
     if (input->waiting_for_bg_response == 0) {
       DLOG("did not get a response for terminal background query");
     }
-    return false;
+    return kNotApplicable;
   }
-  input->waiting_for_bg_response = 0;
-  rbuffer_consumed(input->read_stream.buffer, header_size);
   RBUFFER_EACH(input->read_stream.buffer, c, i) {
     count = i + 1;
+    // Skip the header.
+    if (i < header_size) {
+      continue;
+    }
     if (eat_backslash) {
       done = true;
       break;
@@ -516,8 +524,8 @@ static bool handle_background_color(TermInput *input)
       bad = true;
     }
   }
-  rbuffer_consumed(input->read_stream.buffer, count);
   if (done && !bad && rgb_max[0] && rgb_max[1] && rgb_max[2]) {
+    rbuffer_consumed(input->read_stream.buffer, count);
     double r = (double)rgb[0] / (double)rgb_max[0];
     double g = (double)rgb[1] / (double)rgb_max[1];
     double b = (double)rgb[2] / (double)rgb_max[2];
@@ -526,11 +534,17 @@ static bool handle_background_color(TermInput *input)
     DLOG("bg response: %s", bgvalue);
     loop_schedule_deferred(&main_loop,
                            event_create(set_bg_deferred, 1, bgvalue));
+    input->waiting_for_bg_response = 0;
+  } else if (!done && !bad) {
+    // An incomplete sequence was found, waiting for the next input.
+    return kIncomplete;
   } else {
+    input->waiting_for_bg_response = 0;
+    rbuffer_consumed(input->read_stream.buffer, count);
     DLOG("failed to parse bg response");
-    return false;
+    return kNotApplicable;
   }
-  return true;
+  return kComplete;
 }
 #ifdef UNIT_TESTING
 bool ut_handle_background_color(TermInput *input)
@@ -542,14 +556,15 @@ bool ut_handle_background_color(TermInput *input)
 static void handle_raw_buffer(TermInput *input, bool force)
 {
   HandleState is_paste;
+  HandleState is_bc;
 
   do {
     if (!force
         && (handle_focus_event(input)
             || (is_paste = handle_bracketed_paste(input)) != kNotApplicable
             || handle_forced_escape(input)
-            || handle_background_color(input))) {
-      if (is_paste == kIncomplete) {
+            || (is_bc = handle_background_color(input)) != kNotApplicable)) {
+      if (is_paste == kIncomplete || is_bc == kIncomplete) {
         // Wait for the next input, leaving it in the raw buffer due to an
         // incomplete sequence.
         return;