Merge remote-tracking branch 'upstream/master'

29 files changed, 596 insertions, 159 deletions

diff --git a/src/nvim/README.md b/src/nvim/README.md
index 3032913500..1c1c3c364e 100644
--- a/src/nvim/README.md
+++ b/src/nvim/README.md
@@ -1,14 +1,26 @@
-## Source code overview
+Nvim core source
+================
 
-This document is an overview of how Nvim works internally, focusing on parts
-that are different from Vim. Since Nvim inherited from Vim, some information in
-[its README](https://raw.githubusercontent.com/vim/vim/master/src/README.txt)
-still applies.
+Module-specific details are documented at the top of each module (`terminal.c`,
+`screen.c`, ...).
 
-For module-specific details, read the source code. Some files are extensively
-commented at the top (e.g. terminal.c, screen.c).
+See `:help development` for more guidelines.
 
-### Source file name conventions
+Logs
+----
+
+Low-level log messages sink to `$NVIM_LOG_FILE`.
+
+You can use `LOG_CALLSTACK()` anywhere in the source to log the current
+stacktrace. (Currently Linux-only.)
+
+UI events are logged at level 0 (`DEBUG_LOG_LEVEL`).
+
+    rm -rf build/
+    make CMAKE_EXTRA_FLAGS="-DMIN_LOG_LEVEL=0"
+
+Filename conventions
+--------------------
 
 The source files use extensions to hint about their purpose.
 
@@ -19,10 +31,12 @@ The source files use extensions to hint about their purpose.
 - `*.h.generated.h` - exported functions’ declarations.
 - `*.c.generated.h` - static functions’ declarations.
 
-### Top-level program loops
+Nvim lifecycle
+--------------
+
+Following describes how Nvim processes input.
 
-Let's understand what a Vim-like program does by analyzing the workflow of
-a typical editing session:
+Consider a typical Vim-like editing session:
 
 01. Vim dispays the welcome screen
 02. User types: `:`
@@ -154,7 +168,8 @@ modes managed by the `state_enter` loop:
 - insert mode: `insert_{enter,check,execute}()`(`edit.c`)
 - terminal mode: `terminal_{enter,execute}()`(`terminal.c`)
 
-### Async event support
+Async event support
+-------------------
 
 One of the features Nvim added is the support for handling arbitrary
 asynchronous events, which can include:
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 90a564bb6a..724a8578ac 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1203,8 +1203,8 @@ do_buffer (
      */
     while (buf == curbuf
            && !(curwin->w_closing || curwin->w_buffer->b_locked > 0)
-           && (firstwin != lastwin || first_tabpage->tp_next != NULL)) {
-      if (win_close(curwin, FALSE) == FAIL)
+           && (!ONE_WINDOW || first_tabpage->tp_next != NULL)) {
+      if (win_close(curwin, false) == FAIL)
         break;
     }
 
@@ -4428,15 +4428,17 @@ do_arg_all (
               continue;
             }
           }
-          /* don't close last window */
-          if (firstwin == lastwin
-              && (first_tabpage->tp_next == NULL || !had_tab))
-            use_firstwin = TRUE;
-          else {
+          // don't close last window
+          if (ONE_WINDOW
+              && (first_tabpage->tp_next == NULL || !had_tab)) {
+            use_firstwin = true;
+          } else {
             win_close(wp, !P_HID(buf) && !bufIsChanged(buf));
-            /* check if autocommands removed the next window */
-            if (!win_valid(wpnext))
-              wpnext = firstwin;                /* start all over... */
+            // check if autocommands removed the next window
+            if (!win_valid(wpnext)) {
+              // start all over...
+              wpnext = firstwin;                
+            }
           }
         }
       }
@@ -4593,7 +4595,7 @@ void ex_buffer_all(exarg_T *eap)
                - tabline_height()
                : wp->w_width != Columns)
            || (had_tab > 0 && wp != firstwin))
-          && firstwin != lastwin
+          && !ONE_WINDOW
           && !(wp->w_closing || wp->w_buffer->b_locked > 0)
           ) {
         win_close(wp, FALSE);
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index 32e71f61f7..bfb1b94738 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -793,6 +793,7 @@ static digr_T digraphdefault[] =
   { '/', '-', 0x2020 },
   { '/', '=', 0x2021 },
   { '.', '.', 0x2025 },
+  { ',', '.', 0x2026 },
   { '%', '0', 0x2030 },
   { '1', '\'', 0x2032 },
   { '2', '\'', 0x2033 },
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 08b3d1dbd7..3ec8deb666 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -15141,7 +15141,8 @@ static void f_sockconnect(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
 
   const char *error = NULL;
-  uint64_t id = channel_connect(tcp, address, 50, &error);
+  eval_format_source_name_line((char *)IObuff, sizeof(IObuff));
+  uint64_t id = channel_connect(tcp, address, 50, (char *)IObuff, &error);
 
   if (error) {
     EMSG2(_("connection failed: %s"), error);
@@ -22449,8 +22450,9 @@ static inline bool common_job_start(TerminalJobData *data, typval_T *rettv)
 
 
   if (data->rpc) {
-    // the rpc channel takes over the in and out streams
-    channel_from_process(proc, data->id);
+    eval_format_source_name_line((char *)IObuff, sizeof(IObuff));
+    // RPC channel takes over the in/out streams.
+    channel_from_process(proc, data->id, (char *)IObuff);
   } else {
     wstream_init(proc->in, 0);
     if (proc->out) {
@@ -22775,3 +22777,11 @@ bool eval_has_provider(const char *name)
 
   return false;
 }
+
+/// Writes "<sourcing_name>:<sourcing_lnum>" to `buf[bufsize]`.
+void eval_format_source_name_line(char *buf, size_t bufsize)
+{
+  snprintf(buf, bufsize, "%s:%" PRIdLINENR,
+           (sourcing_name ? sourcing_name : (char_u *)"?"),
+           (sourcing_name ? sourcing_lnum : 0));
+}
diff --git a/src/nvim/ex_cmds.c b/src/nvim/ex_cmds.c
index 0987cb3915..a555fb77e8 100644
--- a/src/nvim/ex_cmds.c
+++ b/src/nvim/ex_cmds.c
@@ -2802,16 +2802,18 @@ void ex_z(exarg_T *eap)
   int j;
   linenr_T lnum = eap->line2;
 
-  /* Vi compatible: ":z!" uses display height, without a count uses
-   * 'scroll' */
-  if (eap->forceit)
+  // Vi compatible: ":z!" uses display height, without a count uses
+  // 'scroll'
+  if (eap->forceit) {
     bigness = curwin->w_height;
-  else if (firstwin == lastwin)
+  } else if (ONE_WINDOW) {
     bigness = curwin->w_p_scr * 2;
-  else
+  } else {
     bigness = curwin->w_height - 3;
-  if (bigness < 1)
+  }
+  if (bigness < 1) {
     bigness = 1;
+  }
 
   x = eap->arg;
   kind = x;
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 5d7246581c..d7821fc636 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -844,8 +844,6 @@ int do_cmdline(char_u *cmdline, LineGetter fgetline,
         break;
       case ET_INTERRUPT:
         break;
-      default:
-        p = vim_strsave((char_u *)_(e_internal));
       }
 
       saved_sourcing_name = sourcing_name;
@@ -3440,6 +3438,11 @@ const char * set_one_cmd_context(
     xp->xp_pattern = (char_u *)arg;
     break;
 
+  case CMD_messages:
+    xp->xp_context = EXPAND_MESSAGES;
+    xp->xp_pattern = (char_u *)arg;
+    break;
+
   case CMD_history:
     xp->xp_context = EXPAND_HISTORY;
     xp->xp_pattern = (char_u *)arg;
@@ -4874,6 +4877,7 @@ static struct {
 #endif
   { EXPAND_MAPPINGS, "mapping" },
   { EXPAND_MENUS, "menu" },
+  { EXPAND_MESSAGES, "messages" },
   { EXPAND_OWNSYNTAX, "syntax" },
   { EXPAND_SYNTIME, "syntime" },
   { EXPAND_SETTINGS, "option" },
@@ -5976,7 +5980,7 @@ static void ex_quit(exarg_T *eap)
     // specified. Example:
     // :h|wincmd w|1q     - don't quit
     // :h|wincmd w|q      - quit
-    if (only_one_window() && (firstwin == lastwin || eap->addr_count == 0)) {
+    if (only_one_window() && (ONE_WINDOW || eap->addr_count == 0)) {
       getout(0);
     }
     /* close window; may free buffer */
@@ -6174,12 +6178,14 @@ static void ex_tabonly(exarg_T *eap)
  */
 void tabpage_close(int forceit)
 {
-  /* First close all the windows but the current one.  If that worked then
-   * close the last window in this tab, that will close it. */
-  if (lastwin != firstwin)
-    close_others(TRUE, forceit);
-  if (lastwin == firstwin)
+  // First close all the windows but the current one.  If that worked then
+  // close the last window in this tab, that will close it.
+  if (!ONE_WINDOW) {
+    close_others(true, forceit);
+  }
+  if (ONE_WINDOW) {
     ex_win_close(forceit, curwin, NULL);
+  }
 }
 
 /*
@@ -9593,6 +9599,16 @@ char_u *get_behave_arg(expand_T *xp, int idx)
   return NULL;
 }
 
+// Function given to ExpandGeneric() to obtain the possible arguments of the
+// ":messages {clear}" command.
+char_u *get_messages_arg(expand_T *xp FUNC_ATTR_UNUSED, int idx)
+{
+  if (idx == 0) {
+    return (char_u *)"clear";
+  }
+  return NULL;
+}
+
 static TriState filetype_detect = kNone;
 static TriState filetype_plugin = kNone;
 static TriState filetype_indent = kNone;
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 5d664b94a8..c029df2f13 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -374,10 +374,9 @@ int do_intthrow(struct condstack *cstack)
   return TRUE;
 }
 
-/*
- * Get an exception message that is to be stored in current_exception->value.
- */
-char_u *get_exception_string(void *value, int type, char_u *cmdname, int *should_free)
+// Get an exception message that is to be stored in current_exception->value.
+char_u *get_exception_string(void *value, except_type_T type, char_u *cmdname,
+                             int *should_free)
 {
   char_u      *ret, *mesg;
   char_u      *p, *val;
@@ -435,13 +434,11 @@ char_u *get_exception_string(void *value, int type, char_u *cmdname, int *should
 }
 
 
-/*
- * Throw a new exception.  Return FAIL when out of memory or it was tried to
- * throw an illegal user exception.  "value" is the exception string for a
- * user or interrupt exception, or points to a message list in case of an
- * error exception.
- */
-static int throw_exception(void *value, int type, char_u *cmdname)
+// Throw a new exception.  Return FAIL when out of memory or it was tried to
+// throw an illegal user exception.  "value" is the exception string for a
+// user or interrupt exception, or points to a message list in case of an
+// error exception.
+static int throw_exception(void *value, except_type_T type, char_u *cmdname)
 {
   except_T    *excp;
   int should_free;
diff --git a/src/nvim/ex_eval.h b/src/nvim/ex_eval.h
index f61e01d25b..d5f8737bf3 100644
--- a/src/nvim/ex_eval.h
+++ b/src/nvim/ex_eval.h
@@ -89,28 +89,29 @@ struct msglist {
   struct msglist      *next;            /* next of several messages in a row */
 };
 
+// The exception types.
+typedef enum
+{
+  ET_USER,       // exception caused by ":throw" command
+  ET_ERROR,      // error exception
+  ET_INTERRUPT   // interrupt exception triggered by Ctrl-C
+} except_type_T;
+
 /*
  * Structure describing an exception.
  * (don't use "struct exception", it's used by the math library).
  */
 typedef struct vim_exception except_T;
 struct vim_exception {
-  int type;                             /* exception type */
-  char_u              *value;           /* exception value */
-  struct msglist      *messages;        /* message(s) causing error exception */
-  char_u              *throw_name;      /* name of the throw point */
-  linenr_T throw_lnum;                  /* line number of the throw point */
-  except_T            *caught;          /* next exception on the caught stack */
+  except_type_T type;                   // exception type
+  char_u              *value;           // exception value
+  struct msglist      *messages;        // message(s) causing error exception
+  char_u              *throw_name;      // name of the throw point
+  linenr_T throw_lnum;                  // line number of the throw point
+  except_T            *caught;          // next exception on the caught stack
 };
 
 /*
- * The exception types.
- */
-#define ET_USER         0       /* exception caused by ":throw" command */
-#define ET_ERROR        1       /* error exception */
-#define ET_INTERRUPT    2       /* interrupt exception triggered by Ctrl-C */
-
-/*
  * Structure to save the error/interrupt/exception state between calls to
  * enter_cleanup() and leave_cleanup().  Must be allocated as an automatic
  * variable by the (common) caller of these functions.
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 0ba6c79a71..1d81a39dfe 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4050,6 +4050,7 @@ ExpandFromContext (
     } tab[] = {
       { EXPAND_COMMANDS, get_command_name, false, true },
       { EXPAND_BEHAVE, get_behave_arg, true, true },
+      { EXPAND_MESSAGES, get_messages_arg, true, true },
       { EXPAND_HISTORY, get_history_arg, true, true },
       { EXPAND_USER_COMMANDS, get_user_commands, false, true },
       { EXPAND_USER_ADDR_TYPE, get_user_cmd_addr_type, false, true },
diff --git a/src/nvim/generators/gen_api_ui_events.lua b/src/nvim/generators/gen_api_ui_events.lua
index acdb25ca67..d2b90db707 100644
--- a/src/nvim/generators/gen_api_ui_events.lua
+++ b/src/nvim/generators/gen_api_ui_events.lua
@@ -119,7 +119,7 @@ for i = 1, #events do
       write_signature(bridge_output, ev, 'UI *ui')
       bridge_output:write('\n{\n')
       bridge_output:write(send)
-      bridge_output:write('  UI_CALL(ui, '..ev.name..', '..argc..', ui'..argv..');\n}\n')
+      bridge_output:write('  UI_BRIDGE_CALL(ui, '..ev.name..', '..argc..', ui'..argv..');\n}\n')
     end
   end
 
@@ -128,6 +128,7 @@ for i = 1, #events do
   call_output:write('\n{\n')
   if ev.remote_only then
     write_arglist(call_output, ev, false)
+    call_output:write('  UI_LOG('..ev.name..', 0);\n')
     call_output:write('  ui_event("'..ev.name..'", args);\n')
   else
     call_output:write('  UI_CALL')
diff --git a/src/nvim/globals.h b/src/nvim/globals.h
index 6d1bd1de12..f08812600f 100644
--- a/src/nvim/globals.h
+++ b/src/nvim/globals.h
@@ -494,6 +494,7 @@ EXTERN int updating_screen INIT(= FALSE);
 EXTERN win_T    *firstwin;              /* first window */
 EXTERN win_T    *lastwin;               /* last window */
 EXTERN win_T    *prevwin INIT(= NULL);  /* previous window */
+# define ONE_WINDOW (firstwin == lastwin)
 /*
  * When using this macro "break" only breaks out of the inner loop. Use "goto"
  * to break out of the tabpage loop.
diff --git a/src/nvim/log.c b/src/nvim/log.c
index f1dbe61dda..252fe5438d 100644
--- a/src/nvim/log.c
+++ b/src/nvim/log.c
@@ -173,6 +173,53 @@ FILE *open_log_file(void)
   return stderr;
 }
 
+#if defined(__linux__)
+# include <execinfo.h>
+void log_callstack(const char *const func_name, const int line_num)
+{
+  void *trace[100];
+  int trace_size = backtrace(trace, ARRAY_SIZE(trace));
+
+  char exepath[MAXPATHL] = { 0 };
+  size_t exepathlen = MAXPATHL;
+  if (os_exepath(exepath, &exepathlen) != 0) {
+    abort();
+  }
+  assert(24 + exepathlen < IOSIZE);  // Must fit in `cmdbuf` below.
+
+  do_log(DEBUG_LOG_LEVEL, func_name, line_num, true, "trace:");
+
+  char cmdbuf[IOSIZE + (20 * ARRAY_SIZE(trace))];
+  snprintf(cmdbuf, sizeof(cmdbuf), "addr2line -e %s -f -p", exepath);
+  for (int i = 1; i < trace_size; i++) {
+    char buf[20];  // 64-bit pointer 0xNNNNNNNNNNNNNNNN with leading space.
+    snprintf(buf, sizeof(buf), " %p", trace[i]);
+    xstrlcat(cmdbuf, buf, sizeof(cmdbuf));
+  }
+  // Now we have a command string like:
+  //    addr2line -e /path/to/exe -f -p 0x123 0x456 ...
+
+  log_lock();
+  FILE *log_file = open_log_file();
+  if (log_file == NULL) {
+    goto end;
+  }
+
+  FILE *fp = popen(cmdbuf, "r");
+  char linebuf[IOSIZE];
+  while (fgets(linebuf, sizeof(linebuf) - 1, fp) != NULL) {
+    fprintf(log_file, "  %s", linebuf);
+  }
+  pclose(fp);
+
+  if (log_file != stderr && log_file != stdout) {
+    fclose(log_file);
+  }
+end:
+  log_unlock();
+}
+#endif
+
 static bool do_log_to_file(FILE *log_file, int log_level,
                            const char *func_name, int line_num, bool eol,
                            const char* fmt, ...)
diff --git a/src/nvim/log.h b/src/nvim/log.h
index 221f0bbaf6..2bd18f5776 100644
--- a/src/nvim/log.h
+++ b/src/nvim/log.h
@@ -61,6 +61,10 @@
                            __VA_ARGS__)
 #endif
 
+#if defined(__linux__)
+# define LOG_CALLSTACK() log_callstack(__func__, __LINE__)
+#endif
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "log.h.generated.h"
 #endif
diff --git a/src/nvim/memory.c b/src/nvim/memory.c
index 74c58fb203..328b96fd5c 100644
--- a/src/nvim/memory.c
+++ b/src/nvim/memory.c
@@ -585,7 +585,7 @@ void free_all_mem(void)
   p_ea = false;
   if (first_tabpage->tp_next != NULL)
     do_cmdline_cmd("tabonly!");
-  if (firstwin != lastwin)
+  if (!ONE_WINDOW)
     do_cmdline_cmd("only!");
 
   /* Free all spell info. */
diff --git a/src/nvim/move.c b/src/nvim/move.c
index d5be4cb8c3..81d46a7f17 100644
--- a/src/nvim/move.c
+++ b/src/nvim/move.c
@@ -1763,7 +1763,7 @@ int onepage(int dir, long count)
 
     loff.fill = 0;
     if (dir == FORWARD) {
-      if (firstwin == lastwin && p_window > 0 && p_window < Rows - 1) {
+      if (ONE_WINDOW && p_window > 0 && p_window < Rows - 1) {
         /* Vi compatible scrolling */
         if (p_window <= 2)
           ++curwin->w_topline;
@@ -1797,7 +1797,7 @@ int onepage(int dir, long count)
         max_topfill();
         continue;
       }
-      if (firstwin == lastwin && p_window > 0 && p_window < Rows - 1) {
+      if (ONE_WINDOW && p_window > 0 && p_window < Rows - 1) {
         /* Vi compatible scrolling (sort of) */
         if (p_window <= 2)
           --curwin->w_topline;
diff --git a/src/nvim/msgpack_rpc/channel.c b/src/nvim/msgpack_rpc/channel.c
index 68ac35bc4e..6fd1af1ba6 100644
--- a/src/nvim/msgpack_rpc/channel.c
+++ b/src/nvim/msgpack_rpc/channel.c
@@ -117,12 +117,15 @@ void channel_teardown(void)
 /// Creates an API channel by starting a process and connecting to its
 /// stdin/stdout. stderr is handled by the job infrastructure.
 ///
-/// @param argv The argument vector for the process. [consumed]
-/// @return The channel id (> 0), on success.
-///         0, on error.
-uint64_t channel_from_process(Process *proc, uint64_t id)
+/// @param proc   process object
+/// @param id     (optional) channel id
+/// @param source description of source function, rplugin name, TCP addr, etc
+///
+/// @return Channel id (> 0), on success. 0, on error.
+uint64_t channel_from_process(Process *proc, uint64_t id, char *source)
 {
-  Channel *channel = register_channel(kChannelTypeProc, id, proc->events);
+  Channel *channel = register_channel(kChannelTypeProc, id, proc->events,
+                                      source);
   incref(channel);  // process channels are only closed by the exit_cb
   channel->data.proc = proc;
 
@@ -138,7 +141,8 @@ uint64_t channel_from_process(Process *proc, uint64_t id)
 /// @param watcher The SocketWatcher ready to accept the connection
 void channel_from_connection(SocketWatcher *watcher)
 {
-  Channel *channel = register_channel(kChannelTypeSocket, 0, NULL);
+  Channel *channel = register_channel(kChannelTypeSocket, 0, NULL,
+                                      watcher->addr);
   socket_watcher_accept(watcher, &channel->data.stream);
   incref(channel);  // close channel only after the stream is closed
   channel->data.stream.internal_close_cb = close_cb;
@@ -148,8 +152,9 @@ void channel_from_connection(SocketWatcher *watcher)
   rstream_start(&channel->data.stream, receive_msgpack, channel);
 }
 
-uint64_t channel_connect(bool tcp, const char *address,
-                         int timeout, const char **error)
+/// @param source description of source function, rplugin name, TCP addr, etc
+uint64_t channel_connect(bool tcp, const char *address, int timeout,
+                         char *source, const char **error)
 {
   if (!tcp) {
     char *path = fix_fname(address);
@@ -161,7 +166,7 @@ uint64_t channel_connect(bool tcp, const char *address,
     xfree(path);
   }
 
-  Channel *channel = register_channel(kChannelTypeSocket, 0, NULL);
+  Channel *channel = register_channel(kChannelTypeSocket, 0, NULL, source);
   if (!socket_connect(&main_loop, &channel->data.stream,
                       tcp, address, timeout, error)) {
     decref(channel);
@@ -329,11 +334,10 @@ bool channel_close(uint64_t id)
   return true;
 }
 
-/// Creates an API channel from stdin/stdout. This is used when embedding
-/// Neovim
+/// Creates an API channel from stdin/stdout. Used to embed Nvim.
 void channel_from_stdio(void)
 {
-  Channel *channel = register_channel(kChannelTypeStdio, 0, NULL);
+  Channel *channel = register_channel(kChannelTypeStdio, 0, NULL, NULL);
   incref(channel);  // stdio channels are only closed on exit
   // read stream
   rstream_init_fd(&main_loop, &channel->data.std.in, 0, CHANNEL_BUFFER_SIZE);
@@ -346,7 +350,7 @@ void channel_from_stdio(void)
 /// when an instance connects to its own named pipe.
 uint64_t channel_create_internal(void)
 {
-  Channel *channel = register_channel(kChannelTypeInternal, 0, NULL);
+  Channel *channel = register_channel(kChannelTypeInternal, 0, NULL, NULL);
   incref(channel);  // internal channel lives until process exit
   return channel->id;
 }
@@ -745,9 +749,12 @@ static void close_cb(Stream *stream, void *data)
   decref(data);
 }
 
+/// @param source description of source function, rplugin name, TCP addr, etc
 static Channel *register_channel(ChannelType type, uint64_t id,
-                                 MultiQueue *events)
+                                 MultiQueue *events, char *source)
 {
+  // Jobs and channels share the same id namespace.
+  assert(id == 0 || !pmap_get(uint64_t)(channels, id));
   Channel *rv = xmalloc(sizeof(Channel));
   rv->events = events ? events : multiqueue_new_child(main_loop.events);
   rv->type = type;
@@ -761,6 +768,14 @@ static Channel *register_channel(ChannelType type, uint64_t id,
   kv_init(rv->call_stack);
   kv_init(rv->delayed_notifications);
   pmap_put(uint64_t)(channels, rv->id, rv);
+
+  ILOG("new channel %" PRIu64 " (%s): %s", rv->id,
+       (type == kChannelTypeProc ? "proc"
+        : (type == kChannelTypeSocket ? "socket"
+           : (type == kChannelTypeStdio ? "stdio"
+              : (type == kChannelTypeInternal ? "internal" : "?")))),
+       (source ? source : "?"));
+
   return rv;
 }
 
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index d891c74fd2..c1676780d8 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -3657,6 +3657,39 @@ nv_gd (
   }
 }
 
+// Return true if line[offset] is not inside a C-style comment or string, false
+// otherwise.
+static bool is_ident(char_u *line, int offset)
+{
+  bool incomment = false;
+  int instring = 0;
+  int prev = 0;
+
+  for (int i = 0; i < offset && line[i] != NUL; i++) {
+    if (instring != 0) {
+      if (prev != '\\' && line[i] == instring) {
+        instring = 0;
+      }
+    } else if ((line[i] == '"' || line[i] == '\'') && !incomment) {
+      instring = line[i];
+    } else {
+      if (incomment) {
+        if (prev == '*' && line[i] == '/') {
+          incomment = false;
+        }
+      } else if (prev == '/' && line[i] == '*') {
+        incomment = true;
+      } else if (prev == '/' && line[i] == '/') {
+        return false;
+      }
+    }
+
+    prev = line[i];
+  }
+
+  return incomment == false && instring == 0;
+}
+
 /*
  * Search for variable declaration of "ptr[len]".
  * When "locally" is true in the current function ("gd"), otherwise in the
@@ -3683,6 +3716,7 @@ find_decl (
   bool retval = true;
   bool incll;
   int searchflags = flags_arg;
+  bool valid;
 
   pat = xmalloc(len + 7);
 
@@ -3717,6 +3751,7 @@ find_decl (
   /* Search forward for the identifier, ignore comment lines. */
   clearpos(&found_pos);
   for (;; ) {
+    valid = false;
     t = searchit(curwin, curbuf, &curwin->w_cursor, FORWARD,
         pat, 1L, searchflags, RE_LAST, (linenr_T)0, NULL);
     if (curwin->w_cursor.lnum >= old_pos.lnum)
@@ -3747,20 +3782,35 @@ find_decl (
       curwin->w_cursor.col = 0;
       continue;
     }
-    if (!locally)       /* global search: use first match found */
+    valid = is_ident(get_cursor_line_ptr(), curwin->w_cursor.col);
+
+    // If the current position is not a valid identifier and a previous match is
+    // present, favor that one instead.
+    if (!valid && found_pos.lnum != 0) {
+      curwin->w_cursor = found_pos;
       break;
-    if (curwin->w_cursor.lnum >= par_pos.lnum) {
-      /* If we previously found a valid position, use it. */
-      if (found_pos.lnum != 0)
+    }
+    // global search: use first match found
+    if (valid && !locally) {
+      break;
+    }
+    if (valid && curwin->w_cursor.lnum >= par_pos.lnum) {
+      // If we previously found a valid position, use it.
+      if (found_pos.lnum != 0) {
         curwin->w_cursor = found_pos;
+      }
       break;
     }
 
-    // For finding a local variable and the match is before the "{" search
-    // to find a later match.  For K&R style function declarations this
-    // skips the function header without types.  Remove SEARCH_START from
-    // flags to avoid getting stuck at one position.
-    found_pos = curwin->w_cursor;
+    // For finding a local variable and the match is before the "{" or
+    // inside a comment, continue searching.  For K&R style function
+    // declarations this skips the function header without types.
+    if (!valid) {
+      clearpos(&found_pos);
+    } else {
+      found_pos = curwin->w_cursor;
+    }
+    // Remove SEARCH_START from flags to avoid getting stuck at one position.
     searchflags &= ~SEARCH_START;
   }
 
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 75b56b4eb4..a6ae022e79 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -4078,7 +4078,7 @@ static char *set_num_option(int opt_idx, char_u *varp, long value,
     }
 
     /* Change window height NOW */
-    if (lastwin != firstwin) {
+    if (!ONE_WINDOW) {
       if (pp == &p_wh && curwin->w_height < p_wh)
         win_setheight((int)p_wh);
       if (pp == &p_hh && curbuf->b_help && curwin->w_height < p_hh)
@@ -4107,7 +4107,7 @@ static char *set_num_option(int opt_idx, char_u *varp, long value,
     }
 
     /* Change window width NOW */
-    if (lastwin != firstwin && curwin->w_width < p_wiw)
+    if (!ONE_WINDOW && curwin->w_width < p_wiw)
       win_setwidth((int)p_wiw);
   }
   /* 'winminwidth' */
@@ -5239,7 +5239,7 @@ static int put_setbool(FILE *fd, char *cmd, char *name, int value)
 
 void comp_col(void)
 {
-  int last_has_status = (p_ls == 2 || (p_ls == 1 && firstwin != lastwin));
+  int last_has_status = (p_ls == 2 || (p_ls == 1 && !ONE_WINDOW));
 
   sc_col = 0;
   ru_col = 0;
diff --git a/