7 files changed, 73 insertions, 14 deletions

diff --git a/src/nvim/event/libuv_process.c b/src/nvim/event/libuv_process.c
index 3da0c386b4..f5a41d151b 100644
--- a/src/nvim/event/libuv_process.c
+++ b/src/nvim/event/libuv_process.c
@@ -8,6 +8,7 @@
 #include "nvim/event/process.h"
 #include "nvim/event/libuv_process.h"
 #include "nvim/log.h"
+#include "nvim/os/os.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "event/libuv_process.c.generated.h"
@@ -24,6 +25,13 @@ int libuv_process_spawn(LibuvProcess *uvproc)
   if (proc->detach) {
       uvproc->uvopts.flags |= UV_PROCESS_DETACHED;
   }
+#ifdef WIN32
+  // libuv collapses the argv to a CommandLineToArgvW()-style string. cmd.exe
+  // expects a different syntax (must be prepared by the caller before now).
+  if (os_shell_is_cmdexe(proc->argv[0])) {
+    uvproc->uvopts.flags |= UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS;
+  }
+#endif
   uvproc->uvopts.exit_cb = exit_cb;
   uvproc->uvopts.cwd = proc->cwd;
   uvproc->uvopts.env = NULL;
diff --git a/src/nvim/memory.c b/src/nvim/memory.c
index b4fdd86a6d..85ec916ba0 100644
--- a/src/nvim/memory.c
+++ b/src/nvim/memory.c
@@ -495,6 +495,13 @@ bool strequal(const char *a, const char *b)
   return (a == NULL && b == NULL) || (a && b && strcmp(a, b) == 0);
 }
 
+/// Case-insensitive `strequal`.
+bool striequal(const char *a, const char *b)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  return (a == NULL && b == NULL) || (a && b && STRICMP(a, b) == 0);
+}
+
 /*
  * Avoid repeating the error message many times (they take 1 second each).
  * Did_outofmem_msg is reset when a character is read.
diff --git a/src/nvim/misc1.c b/src/nvim/misc1.c
index 0b74b4437e..8d93505be3 100644
--- a/src/nvim/misc1.c
+++ b/src/nvim/misc1.c
@@ -2678,7 +2678,8 @@ void fast_breakcheck(void)
   }
 }
 
-// Call shell. Calls os_call_shell, with 'shellxquote' added.
+// os_call_shell wrapper. Handles 'verbose', :profile, and v:shell_error.
+// Invalidates cached tags.
 int call_shell(char_u *cmd, ShellOpts opts, char_u *extra_shell_arg)
 {
   int retval;
@@ -2686,8 +2687,7 @@ int call_shell(char_u *cmd, ShellOpts opts, char_u *extra_shell_arg)
 
   if (p_verbose > 3) {
     verbose_enter();
-    smsg(_("Calling shell to execute: \"%s\""),
-         cmd == NULL ? p_sh : cmd);
+    smsg(_("Calling shell to execute: \"%s\""), cmd == NULL ? p_sh : cmd);
     ui_putc('\n');
     verbose_leave();
   }
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 4ca63f2efe..4e7be63b63 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -2051,7 +2051,11 @@ return {
       secure=true,
       vi_def=true,
       varname='p_srr',
-      defaults={if_true={vi=">"}}
+      defaults={
+        condition='WIN32',
+        if_true={vi=">%s 2>&1"},
+        if_false={vi=">"}
+      }
     },
     {
       full_name='shellslash', abbreviation='ssl',
diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
index 12c2da6152..ad51e598c1 100644
--- a/src/nvim/os/env.c
+++ b/src/nvim/os/env.c
@@ -1,11 +1,8 @@
-// env.c -- environment variable access
+// Environment inspection
 
 #include <assert.h>
-
 #include <uv.h>
 
-// vim.h must be included before charset.h (and possibly others) or things
-// blow up
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/charset.h"
@@ -919,3 +916,20 @@ bool os_term_is_nice(void)
     || NULL != os_getenv("KONSOLE_DBUS_SESSION");
 #endif
 }
+
+/// Returns true if `sh` looks like it resolves to "cmd.exe".
+bool os_shell_is_cmdexe(const char *sh)
+  FUNC_ATTR_NONNULL_ALL
+{
+  if (*sh == NUL) {
+    return false;
+  }
+  if (striequal(sh, "$COMSPEC")) {
+    const char *comspec = os_getenv("COMSPEC");
+    return striequal("cmd.exe", (char *)path_tail((char_u *)comspec));
+  }
+  if (striequal(sh, "cmd.exe") || striequal(sh, "cmd")) {
+    return true;
+  }
+  return striequal("cmd.exe", (char *)path_tail((char_u *)sh));
+}
diff --git a/src/nvim/os/shell.c b/src/nvim/os/shell.c
index b449cc3d5a..5cc9d4b79b 100644
--- a/src/nvim/os/shell.c
+++ b/src/nvim/os/shell.c
@@ -124,11 +124,9 @@ int os_call_shell(char_u *cmd, ShellOpts opts, char_u *extra_args)
   }
 
   size_t nread;
-
   int exitcode = do_os_system(shell_build_argv((char *)cmd, (char *)extra_args),
                               input.data, input.len, output_ptr, &nread,
                               emsg_silent, forward_output);
-
   xfree(input.data);
 
   if (output) {
diff --git a/src/nvim/strings.c b/src/nvim/strings.c
index 87e066d80a..8a1a3beddd 100644
--- a/src/nvim/strings.c
+++ b/src/nvim/strings.c
@@ -198,8 +198,16 @@ char_u *vim_strsave_shellescape(const char_u *string,
   /* First count the number of extra bytes required. */
   size_t length = STRLEN(string) + 3;       // two quotes and a trailing NUL
   for (const char_u *p = string; *p != NUL; mb_ptr_adv(p)) {
-    if (*p == '\'')
-      length += 3;                      /* ' => '\'' */
+#ifdef WIN32
+    if (!p_ssl) {
+      if (*p == '"') {
+        length++;                       // " -> ""
+      }
+    } else
+#endif
+    if (*p == '\'') {
+      length += 3;                      // ' => '\''
+    }
     if ((*p == '\n' && (csh_like || do_newline))
         || (*p == '!' && (csh_like || do_special))) {
       ++length;                         /* insert backslash */
@@ -216,10 +224,25 @@ char_u *vim_strsave_shellescape(const char_u *string,
   escaped_string = xmalloc(length);
   d = escaped_string;
 
-  /* add opening quote */
+  // add opening quote
+#ifdef WIN32
+  if (!p_ssl) {
+    *d++ = '"';
+  } else
+#endif
   *d++ = '\'';
 
   for (const char_u *p = string; *p != NUL; ) {
+#ifdef WIN32
+    if (!p_ssl) {
+      if (*p == '"') {
+        *d++ = '"';
+        *d++ = '"';
+        p++;
+        continue;
+      }
+    } else
+#endif
     if (*p == '\'') {
       *d++ = '\'';
       *d++ = '\\';
@@ -246,7 +269,12 @@ char_u *vim_strsave_shellescape(const char_u *string,
     MB_COPY_CHAR(p, d);
   }
 
-  /* add terminating quote and finish with a NUL */
+  // add terminating quote and finish with a NUL
+# ifdef WIN32
+  if (!p_ssl) {
+    *d++ = '"';
+  } else
+# endif
   *d++ = '\'';
   *d = NUL;