ex_getln: Fix “echoerr msg not shown” problem

This also attempted to fix problem with cancelling input() on error by avoiding 
standard error printing facilities (assumed thrown error message is the 
problem), but with no luck so far.

1 files changed, 30 insertions, 22 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 9c494a2640..444a3e5b11 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -64,6 +64,7 @@
 #include "nvim/os/time.h"
 #include "nvim/lib/kvec.h"
 #include "nvim/api/private/helpers.h"
+#include "nvim/highlight_defs.h"
 
 /*
  * Variables shared between getcmdline(), redrawcmdline() and others.
@@ -2202,6 +2203,13 @@ enum { MAX_CB_ERRORS = 1 };
 ///         to do.
 static bool color_cmdline(void)
 {
+  bool printed_errmsg = false;
+#define PRINT_ERRMSG(...) \
+  do { \
+    msg_putchar('\n'); \
+    msg_printf_attr(hl_attr(HLF_E)|MSG_HIST, __VA_ARGS__); \
+    printed_errmsg = true; \
+  } while (0)
   bool ret = true;
   kv_size(ccline_colors) = 0;
 
@@ -2274,7 +2282,7 @@ static bool color_cmdline(void)
     goto color_cmdline_error;
   }
   if (tv.v_type != VAR_LIST) {
-    emsgf(_("E5400: Callback should return list"));
+    PRINT_ERRMSG(_("E5400: Callback should return list"));
     goto color_cmdline_error;
   }
   if (tv.vval.v_list == NULL) {
@@ -2285,13 +2293,13 @@ static bool color_cmdline(void)
   for (const listitem_T *li = tv.vval.v_list->lv_first;
        li != NULL; li = li->li_next, i++) {
     if (li->li_tv.v_type != VAR_LIST) {
-      emsgf(_("E5401: List item %i is not a List"), i);
+      PRINT_ERRMSG(_("E5401: List item %i is not a List"), i);
       goto color_cmdline_error;
     }
     const list_T *const l = li->li_tv.vval.v_list;
     if (tv_list_len(l) != 3) {
-      emsgf(_("E5402: List item %i has incorrect length: %li /= 3"),
-            i, tv_list_len(l));
+      PRINT_ERRMSG(_("E5402: List item %i has incorrect length: %li /= 3"),
+                   i, tv_list_len(l));
       goto color_cmdline_error;
     }
     bool error = false;
@@ -2299,13 +2307,13 @@ static bool color_cmdline(void)
     if (error) {
       goto color_cmdline_error;
     } else if (!(prev_end <= start && start < ccline.cmdlen)) {
-      emsgf(_("E5403: Chunk %i start %" PRIdVARNUMBER " not in range "
-              "[%" PRIdVARNUMBER ", %i)"),
-            i, start, prev_end, ccline.cmdlen);
+      PRINT_ERRMSG(_("E5403: Chunk %i start %" PRIdVARNUMBER " not in range "
+                     "[%" PRIdVARNUMBER ", %i)"),
+                   i, start, prev_end, ccline.cmdlen);
       goto color_cmdline_error;
     } else if (utf8len_tab_zero[(uint8_t)ccline.cmdbuff[start]] == 0) {
-      emsgf(_("E5405: Chunk %i start %" PRIdVARNUMBER " splits multibyte "
-              "character"), i, start);
+      PRINT_ERRMSG(_("E5405: Chunk %i start %" PRIdVARNUMBER " splits "
+                     "multibyte character"), i, start);
       goto color_cmdline_error;
     }
     if (start != prev_end) {
@@ -2320,14 +2328,14 @@ static bool color_cmdline(void)
     if (error) {
       goto color_cmdline_error;
     } else if (!(start < end && end <= ccline.cmdlen)) {
-      emsgf(_("E5404: Chunk %i end %" PRIdVARNUMBER " not in range "
-              "(%" PRIdVARNUMBER ", %i]"),
-            i, end, start, ccline.cmdlen);
+      PRINT_ERRMSG(_("E5404: Chunk %i end %" PRIdVARNUMBER " not in range "
+                     "(%" PRIdVARNUMBER ", %i]"),
+                   i, end, start, ccline.cmdlen);
       goto color_cmdline_error;
     } else if (end < ccline.cmdlen
                && utf8len_tab_zero[(uint8_t)ccline.cmdbuff[end]] == 0) {
-      emsgf(_("E5406: Chunk %i end %" PRIdVARNUMBER " splits multibyte "
-              "character"), i, end);
+      PRINT_ERRMSG(_("E5406: Chunk %i end %" PRIdVARNUMBER " splits multibyte "
+                     "character"), i, end);
       goto color_cmdline_error;
     }
     prev_end = end;
@@ -2364,19 +2372,19 @@ color_cmdline_end:
   return ret;
 color_cmdline_error:
   if (ERROR_SET(&err)) {
-    emsgf(_("E5407: Callback has thrown an exception: %s"), err.msg);
+    PRINT_ERRMSG(_("E5407: Callback has thrown an exception: %s"), err.msg);
     api_clear_error(&err);
   }
+  assert(printed_errmsg);
+
   prev_prompt_errors++;
   kv_size(ccline_colors) = 0;
-  if (did_emsg) {
-    did_emsg = false;
-    prev_prompt_errors += MAX_CB_ERRORS;
-    redrawcmdline();
-    prev_prompt_errors -= MAX_CB_ERRORS;
-    ret = false;
-  }
+  prev_prompt_errors += MAX_CB_ERRORS;
+  redrawcmdline();
+  prev_prompt_errors -= MAX_CB_ERRORS;
+  ret = false;
   goto color_cmdline_end;
+#undef PRINT_ERRMSG
 }
 
 /*