MAINT-8087: Use env vars from VMP for AppData\Roaming and Local.

On Windows, when logged in with a non-ASCII username, every one of the three
documented APIs -- SHGetSpecialFolderPath(), SHGetFolderPath() and
SHGetKnownFolderPath() -- fails to retrieve any pathname at all. We cannot
account for the fact that the oldest of these continues to work with the
release viewer and within a Python script (though not, curiously, from a
Python interactive session). With a non-ASCII username, they consistently fail
when called from an Alex Ivy viewer build: "The filename, directory name, or
volume label syntax is incorrect."

Empirically, with a non-ASCII username, the preset APPDATA and LOCALAPPDATA
environment variables are also useless, e.g. c:\Users\??????\AppData\Roaming
where those are, yup, actual question marks.

Empirically, the VMP is able to successfully call SHGetFolderPath() to
retrieve both AppData\Roaming and AppData\Local. Therefore, we make the VMP
set the APPDATA and LOCALAPPDATA environment variables to the UTF-8 encoded
correct pathnames. Instead of calling SHGetSomethingFolderPath() at all, make
LLDir_Win32 retrieve those environment variables.

Make LLFile::mkdir() treat "directory already exists" as a success case. Every
single call fell into one of two categories: either it didn't check success at
all, or it tested specially to exempt errno == EEXIST. Migrate that test into
mkdir(); eliminate it from call sites.

Make LLDir::append() and add() convenience functions accept variadic
arguments. Replace add(add()...) constructs, as well as clumsy concatenations
of directory names and getDirDelimiter(), with simple variadic add() calls.

2 files changed, 9 insertions, 1 deletions

diff --git a/indra/llcommon/llfile.cpp b/indra/llcommon/llfile.cpp
index 7b559861bb..8aa41035b9 100644
--- a/indra/llcommon/llfile.cpp
+++ b/indra/llcommon/llfile.cpp
@@ -182,7 +182,14 @@ int	LLFile::mkdir(const std::string& dirname, int perms)
 	int rc = ::mkdir(dirname.c_str(), (mode_t)perms);
 #endif
 	// We often use mkdir() to ensure the existence of a directory that might
-	// already exist. Don't spam the log if it does.
+	// already exist. There is no known case in which we want to call out as
+	// an error the requested directory already existing.
+	if (rc < 0 && errno == EEXIST)
+	{
+		// this is not the error you want, move along
+		return 0;
+	}
+	// anything else might be a problem
 	return warnif("mkdir", dirname, rc, EEXIST);
 }
 
diff --git a/indra/llcommon/llfile.h b/indra/llcommon/llfile.h
index 37eb75881c..ba935b8714 100644
--- a/indra/llcommon/llfile.h
+++ b/indra/llcommon/llfile.h
@@ -69,6 +69,7 @@ public:
 
 	// perms is a permissions mask like 0777 or 0700.  In most cases it will
 	// be overridden by the user's umask.  It is ignored on Windows.
+	// mkdir() considers "directory already exists" to be SUCCESS.
 	static	int		mkdir(const std::string& filename, int perms = 0700);
 
 	static	int		rmdir(const std::string& filename);