1 files changed, 43 insertions, 21 deletions

diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
index 8620c79069..5b1cb01976 100644
--- a/src/nvim/os/env.c
+++ b/src/nvim/os/env.c
@@ -13,9 +13,9 @@
 #include "nvim/buffer_defs.h"
 #include "nvim/charset.h"
 #include "nvim/cmdexpand.h"
+#include "nvim/cmdexpand_defs.h"
 #include "nvim/eval.h"
-#include "nvim/func_attr.h"
-#include "nvim/gettext.h"
+#include "nvim/gettext_defs.h"
 #include "nvim/globals.h"
 #include "nvim/log.h"
 #include "nvim/macros_defs.h"
@@ -25,8 +25,10 @@
 #include "nvim/option_vars.h"
 #include "nvim/os/fs.h"
 #include "nvim/os/os.h"
+#include "nvim/os/os_defs.h"
 #include "nvim/path.h"
 #include "nvim/strings.h"
+#include "nvim/types_defs.h"
 #include "nvim/version.h"
 #include "nvim/vim_defs.h"
 
@@ -46,6 +48,10 @@
 # include <sys/utsname.h>
 #endif
 
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "os/env.c.generated.h"
+#endif
+
 // Because `uv_os_getenv` requires allocating, we must manage a map to maintain
 // the behavior of `os_getenv`.
 static PMap(cstr_t) envmap = MAP_INIT;
@@ -55,8 +61,7 @@ static PMap(cstr_t) envmap = MAP_INIT;
 const char *os_getenv(const char *name)
   FUNC_ATTR_NONNULL_ALL
 {
-  char *e;
-  size_t size = 64;
+  char *e = NULL;
   if (name[0] == '\0') {
     return NULL;
   }
@@ -72,23 +77,31 @@ const char *os_getenv(const char *name)
     }
     pmap_del2(&envmap, name);
   }
-  e = xmalloc(size);
-  r = uv_os_getenv(name, e, &size);
+#define INIT_SIZE 64
+  size_t size = INIT_SIZE;
+  char buf[INIT_SIZE];
+  r = uv_os_getenv(name, buf, &size);
   if (r == UV_ENOBUFS) {
-    e = xrealloc(e, size);
+    e = xmalloc(size);
     r = uv_os_getenv(name, e, &size);
-  }
-  if (r != 0 || size == 0 || e[0] == '\0') {
-    xfree(e);
+    if (r != 0 || size == 0 || e[0] == '\0') {
+      XFREE_CLEAR(e);
+      goto end;
+    }
+  } else if (r != 0 || size == 0 || buf[0] == '\0') {
     e = NULL;
     goto end;
+  } else {
+    // NB: `size` param of uv_os_getenv() includes the NUL-terminator,
+    // except when it does not include the NUL-terminator.
+    e = xmemdupz(buf, size);
   }
   pmap_put(cstr_t)(&envmap, xstrdup(name), e);
 end:
   if (r != 0 && r != UV_ENOENT && r != UV_UNKNOWN) {
     ELOG("uv_os_getenv(%s) failed: %d %s", name, r, uv_err_name(r));
   }
-  return (e == NULL || size == 0 || e[0] == '\0') ? NULL : e;
+  return e;
 }
 
 /// Returns true if environment variable `name` is defined (even if empty).
@@ -507,6 +520,17 @@ void free_homedir(void)
   xfree(homedir);
 }
 
+void free_envmap(void)
+{
+  cstr_t name;
+  ptr_t e;
+  map_foreach(&envmap, name, e, {
+    xfree((char *)name);
+    xfree(e);
+  });
+  map_destroy(cstr_t, &envmap);
+}
+
 #endif
 
 /// Call expand_env() and store the result in an allocated string.
@@ -562,6 +586,9 @@ void expand_env_esc(char *restrict srcp, char *restrict dst, int dstlen, bool es
   bool copy_char;
   bool mustfree;  // var was allocated, need to free it later
   bool at_start = true;  // at start of a name
+#if defined(BACKSLASH_IN_FILENAME)
+  char *const save_dst = dst;
+#endif
 
   int prefix_len = (prefix == NULL) ? 0 : (int)strlen(prefix);
 
@@ -572,7 +599,7 @@ void expand_env_esc(char *restrict srcp, char *restrict dst, int dstlen, bool es
     if (src[0] == '`' && src[1] == '=') {
       var = src;
       src += 2;
-      (void)skip_expr(&src, NULL);
+      skip_expr(&src, NULL);
       if (*src == '`') {
         src++;
       }
@@ -604,7 +631,7 @@ void expand_env_esc(char *restrict srcp, char *restrict dst, int dstlen, bool es
           while (c-- > 0 && *tail != NUL && *tail != '}') {
             *var++ = *tail++;
           }
-        } else  // NOLINT
+        } else
 #endif
         {
           while (c-- > 0 && *tail != NUL && vim_isIDc((uint8_t)(*tail))) {
@@ -702,7 +729,7 @@ void expand_env_esc(char *restrict srcp, char *restrict dst, int dstlen, bool es
         // with it, skip a character
         if (after_pathsep(dst, dst + c)
 #if defined(BACKSLASH_IN_FILENAME)
-            && dst[-1] != ':'
+            && (dst == save_dst || dst[-1] != ':')
 #endif
             && vim_ispathsep(*tail)) {
           tail++;
@@ -904,10 +931,7 @@ char *vim_getenv(const char *name)
   // Don't do this when default_vimruntime_dir is non-empty.
   char *vim_path = NULL;
   if (vimruntime
-#ifdef HAVE_PATHDEF
-      && *default_vimruntime_dir == NUL
-#endif
-      ) {
+      && *default_vimruntime_dir == NUL) {
     kos_env_path = os_getenv("VIM");
     if (kos_env_path != NULL) {
       vim_path = vim_version_dir(kos_env_path);
@@ -966,7 +990,6 @@ char *vim_getenv(const char *name)
     assert(vim_path != exe_name);
   }
 
-#ifdef HAVE_PATHDEF
   // When there is a pathdef.c file we can use default_vim_dir and
   // default_vimruntime_dir
   if (vim_path == NULL) {
@@ -980,7 +1003,6 @@ char *vim_getenv(const char *name)
       }
     }
   }
-#endif
 
   // Set the environment variable, so that the new value can be found fast
   // next time, and others can also use it (e.g. Perl).
@@ -1051,7 +1073,7 @@ size_t home_replace(const buf_T *const buf, const char *src, char *const dst, si
     size_t usedlen = 0;
     size_t flen = strlen(homedir_env_mod);
     char *fbuf = NULL;
-    (void)modify_fname(":p", false, &usedlen, &homedir_env_mod, &fbuf, &flen);
+    modify_fname(":p", false, &usedlen, &homedir_env_mod, &fbuf, &flen);
     flen = strlen(homedir_env_mod);
     assert(homedir_env_mod != homedir_env);
     if (vim_ispathsep(homedir_env_mod[flen - 1])) {