symlinks: add gating for Windows symlinks through store requirements

Summary: This should allow in later diffs to enable symlinks on Windows if users have `windowssymlinks` on their repo store requirements. Additionally, it adds the aforementioned requirement to new repos cloned with the `symlinks.force-enable` config.

Reviewed By: muirdm

Differential Revision: D43456961

fbshipit-source-id: bd2f5a1cb6c3b647ebccb0de556959758a4d7fe2

eden/scm/edenscm/dirstate.py

@@ -267,6 +267,8 @@ class dirstate(object):
 
     @util.propertycache
     def _checklink(self) -> bool:
+        if pycompat.iswindows and "windowssymlinks" not in self._repo.requirements:
+            return False
         return util.checklink(self._root)
 
     @util.propertycache

eden/scm/edenscm/hg.py

@@ -280,8 +280,13 @@ def share(
         checkout = None
 
     sharedpath = srcrepo.sharedpath  # if our source is already sharing
+    requirements = srcrepo.requirements.copy()
 
-    destwvfs = vfsmod.vfs(dest, realpath=True)
+    destwvfs = vfsmod.vfs(
+        dest,
+        realpath=True,
+        disablesymlinks=pycompat.iswindows and "windowssymlinks" not in requirements,
+    )
     destvfs = vfsmod.vfs(
         os.path.join(destwvfs.base, ui.identity.dotdir()), realpath=True
     )
@@ -293,8 +298,6 @@ def share(
         destwvfs.mkdir()
     destvfs.makedir()
 
-    requirements = srcrepo.requirements.copy()
-
     if relative:
         try:
             sharedpath = os.path.relpath(sharedpath, destvfs.base)

eden/scm/edenscm/localrepo.py

@@ -336,6 +336,8 @@ class localrepository(object):
         "treestate",
         "storerequirements",
         "lfs",
+        # enable symlinks on Windows
+        "windowssymlinks",
     }
     _basestoresupported = {
         "visibleheads",
@@ -428,9 +430,7 @@ class localrepository(object):
         self.requirements = set()
         self.storerequirements = set()
 
-        # wvfs: rooted at the repository root, used to access the working copy
-        self.wvfs = vfsmod.vfs(path, expandpath=True, realpath=True, cacheaudited=False)
-        self.root = self.wvfs.base
+        self.root = os.path.realpath(util.expandpath(path))
 
         self.baseui = baseui
         self.ui = baseui.copy()
@@ -468,9 +468,6 @@ class localrepository(object):
 
         self._loadextensions()
 
-        cacheaudited = self.ui.configbool("unsafe", "wvfsauditorcache")
-        self.wvfs.audit._cached = cacheaudited
-
         self.supported = self._featuresetup(self.featuresetupfuncs, self._basesupported)
         self.storesupported = self._featuresetup(
             self.storefeaturesetupfuncs, self._basestoresupported
@@ -489,6 +486,21 @@ class localrepository(object):
             if inst.errno != errno.ENOENT:
                 raise
 
+        # wvfs: rooted at the repository root, used to access the working copy
+        disablesymlinks = (
+            pycompat.iswindows and "windowssymlinks" not in self.requirements
+        )
+        self.wvfs = vfsmod.vfs(
+            path,
+            expandpath=True,
+            realpath=True,
+            cacheaudited=False,
+            disablesymlinks=disablesymlinks,
+        )
+
+        cacheaudited = self.ui.configbool("unsafe", "wvfsauditorcache")
+        self.wvfs.audit._cached = cacheaudited
+
         cachepath = self.localvfs.join("cache")
         self.sharedpath = self.path
         self.sharedroot = self.root

eden/scm/edenscm/vfs.py

@@ -411,6 +411,7 @@ class vfs(abstractvfs):
         cacheaudited: bool = False,
         expandpath: bool = False,
         realpath: bool = False,
+        disablesymlinks: bool = False,
     ) -> None:
         if expandpath:
             base = util.expandpath(base)
@@ -424,9 +425,12 @@ class vfs(abstractvfs):
             self.audit = lambda path, mode=None: True
         self.createmode = None
         self._trustnlink = None
+        self._disablesymlinks = disablesymlinks
 
     @util.propertycache
     def _cansymlink(self) -> bool:
+        if self._disablesymlinks:
+            return False
         return util.checklink(self.base)
 
     @util.propertycache

eden/scm/lib/repo/src/init.rs

@@ -137,6 +137,12 @@ fn write_requirements(path: &Path, config: &ConfigSet) -> Result<(), InitError>
     {
         requirements.insert("generaldelta");
     }
+    if config
+        .get_or_default("experimental", "windows-symlinks")
+        .unwrap_or_default()
+    {
+        requirements.insert("windowssymlinks");
+    }
 
     write_requirements_file(path, requirements)
 }