Merge #4837 from justinmk/os_resolve_shortcut

os_resolve_shortcut

src/nvim/buffer.c

@@ -4030,8 +4030,8 @@ void fname_expand(buf_T *buf, char_u **ffname, char_u **sfname)
   if (!buf->b_p_bin) {
     char_u  *rfname;
 
-    /* If the file name is a shortcut file, use the file it links to. */
+    // If the file name is a shortcut file, use the file it links to.
-    rfname = mch_resolve_shortcut(*ffname);
+    rfname = os_resolve_shortcut(*ffname);
     if (rfname != NULL) {
       xfree(*ffname);
       *ffname = rfname;

src/nvim/eval.c

@@ -13637,12 +13637,13 @@ static void f_resolve(typval_T *argvars, typval_T *rettv)
   {
     char_u  *v = NULL;
 
-    v = mch_resolve_shortcut(p);
+    v = os_resolve_shortcut(p);
-    if (v != NULL)
+    if (v != NULL) {
       rettv->vval.v_string = v;
-    else
+    } else {
       rettv->vval.v_string = vim_strsave(p);
     }
+  }
 #else
 # ifdef HAVE_READLINK
   {

src/nvim/mbyte.c

@@ -1885,6 +1885,86 @@ static int utf_strnicmp(char_u *s1, char_u *s2, size_t n1, size_t n2)
   return n1 == 0 ? -1 : 1;
 }
 
+#ifdef WIN32
+#ifndef CP_UTF8
+# define CP_UTF8 65001  /* magic number from winnls.h */
+#endif
+
+int utf8_to_utf16(const char *str, WCHAR **strw)
+  FUNC_ATTR_NONNULL_ALL
+{
+  ssize_t wchar_len = 0;
+
+  // Compute the length needed to store the converted widechar string.
+  wchar_len = MultiByteToWideChar(CP_UTF8,
+                                  0,     // dwFlags: must be 0 for utf8
+                                  str,   // lpMultiByteStr: string to convert
+                                  -1,    // -1 => process up to NUL
+                                  NULL,  // lpWideCharStr: converted string
+                                  0);    // 0  => return length, don't convert
+  if (wchar_len == 0) {
+    return GetLastError();
+  }
+
+  ssize_t buf_sz = wchar_len * sizeof(WCHAR);
+
+  if (buf_sz == 0) {
+    *strw = NULL;
+    return 0;
+  }
+
+  char *buf = xmalloc(buf_sz);
+  char *pos = buf;
+
+  int r = MultiByteToWideChar(CP_UTF8,
+                              0,
+                              str,
+                              -1,
+                              (WCHAR *)pos,
+                              wchar_len);
+  assert(r == wchar_len);
+  *strw = (WCHAR *)pos;
+
+  return 0;
+}
+
+int utf16_to_utf8(const WCHAR *strw, char **str)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // Compute the space required to store the string as UTF-8.
+  ssize_t utf8_len = WideCharToMultiByte(CP_UTF8,
+                                         0,
+                                         strw,
+                                         -1,
+                                         NULL,
+                                         0,
+                                         NULL,
+                                         NULL);
+  if (utf8_len == 0) {
+    return GetLastError();
+  }
+
+  ssize_t buf_sz = utf8_len * sizeof(char);
+  char *buf = xmalloc(buf_sz);
+  char *pos = buf;
+
+  // Convert string to UTF-8.
+  int r = WideCharToMultiByte(CP_UTF8,
+                              0,
+                              strw,
+                              -1,
+                              (LPSTR *)pos,
+                              utf8_len,
+                              NULL,
+                              NULL);
+  assert(r == utf8_len);
+  *str = pos;
+
+  return 0;
+}
+
+#endif
+
 /*
  * Version of strnicmp() that handles multi-byte characters.
  * Needed for Big5, Shift-JIS and UTF-8 encoding.  Other DBCS encodings can

src/nvim/os/fs.c

@@ -25,6 +25,10 @@
 #include "nvim/path.h"
 #include "nvim/strings.h"
 
+#ifdef WIN32
+#include "nvim/mbyte.h"  // for utf8_to_utf16, utf16_to_utf8
+#endif
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "os/fs.c.generated.h"
 #endif
@@ -929,3 +933,93 @@ bool os_fileid_equal_fileinfo(const FileID *file_id,
          && file_id->device_id == file_info->stat.st_dev;
 }
 
+#ifdef WIN32
+# include <shlobj.h>
+
+/// When "fname" is the name of a shortcut (*.lnk) resolve the file it points
+/// to and return that name in allocated memory.
+/// Otherwise NULL is returned.
+char_u * os_resolve_shortcut(char_u *fname)
+{
+  HRESULT hr;
+  IPersistFile *ppf = NULL;
+  OLECHAR wsz[MAX_PATH];
+  char_u *rfname = NULL;
+  int len;
+  int conversion_result;
+  IShellLinkW *pslw = NULL;
+  WIN32_FIND_DATAW ffdw;
+
+  // Check if the file name ends in ".lnk". Avoid calling CoCreateInstance(),
+  // it's quite slow.
+  if (fname == NULL) {
+    return rfname;
+  }
+  len = (int)STRLEN(fname);
+  if (len <= 4 || STRNICMP(fname + len - 4, ".lnk", 4) != 0) {
+    return rfname;
+  }
+
+  CoInitialize(NULL);
+
+  // create a link manager object and request its interface
+  hr = CoCreateInstance(&CLSID_ShellLink, NULL, CLSCTX_INPROC_SERVER,
+                        &IID_IShellLinkW, (void **)&pslw);
+  if (hr == S_OK) {
+    WCHAR *p;
+    int conversion_result = utf8_to_utf16((char *)fname, &p);
+    if (conversion_result != 0) {
+      EMSG2("utf8_to_utf16 failed: %s", uv_strerror(conversion_result));
+    }
+
+    if (p != NULL) {
+      // Get a pointer to the IPersistFile interface.
+      hr = pslw->lpVtbl->QueryInterface(
+          pslw, &IID_IPersistFile, (void **)&ppf);
+      if (hr != S_OK) {
+        goto shortcut_errorw;
+      }
+
+      // "load" the name and resolve the link
+      hr = ppf->lpVtbl->Load(ppf, p, STGM_READ);
+      if (hr != S_OK) {
+        goto shortcut_errorw;
+      }
+
+#  if 0  // This makes Vim wait a long time if the target does not exist.
+      hr = pslw->lpVtbl->Resolve(pslw, NULL, SLR_NO_UI);
+      if (hr != S_OK) {
+        goto shortcut_errorw;
+      }
+#  endif
+
+      // Get the path to the link target.
+      ZeroMemory(wsz, MAX_PATH * sizeof(WCHAR));
+      hr = pslw->lpVtbl->GetPath(pslw, wsz, MAX_PATH, &ffdw, 0);
+      if (hr == S_OK && wsz[0] != NUL) {
+        int conversion_result = utf16_to_utf8(wsz, &rfname);
+        if (conversion_result != 0) {
+          EMSG2("utf16_to_utf8 failed: %s", uv_strerror(conversion_result));
+        }
+      }
+
+shortcut_errorw:
+      xfree(p);
+      goto shortcut_end;
+    }
+  }
+
+shortcut_end:
+  // Release all interface pointers (both belong to the same object)
+  if (ppf != NULL) {
+    ppf->lpVtbl->Release(ppf);
+  }
+  if (pslw != NULL) {
+    pslw->lpVtbl->Release(pslw);
+  }
+
+  CoUninitialize();
+  return rfname;
+}
+
+#endif