commit 2099dca5d3c7e65ba8e56a42d7841b39f53d7d16
Author: Enrico Forestieri <[email protected]>
Date: Mon Jan 4 23:00:42 2021 +0100
Do not replace nonexistent environment variables
References to environment variables embedded in a filename are expanded
and replaced by their value. However, if a variable does not exist, its
reference is simply erased from the filename, causing havoc (see #7801).
This has been like that since ever and cannot be changed, both for
backward compatibility and because this feature is currently used in
the Windows installer.
A possible backward compatible strategy is leaving as is the reference
to the environment variable (introduced by a $ sign) in the filename
if it does not exist. This is done in this patch, which also assumes
that an escape character is never used in a filename (inserting a $ in
the filename is easy, but I don't think one is able to easily insert
an escape character).
---
src/support/filetools.cpp | 15 ++++++++++++++-
1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/src/support/filetools.cpp b/src/support/filetools.cpp
index a5168d4..16e6da4 100644
--- a/src/support/filetools.cpp
+++ b/src/support/filetools.cpp
@@ -683,8 +683,12 @@ string const onlyFileName(string const & fname)
// Search the string for ${VAR} and $VAR and replace VAR using getenv.
+// If VAR does not exist, ${VAR} and $VAR are left as is in the string.
string const replaceEnvironmentPath(string const & path)
{
+ if (!contains(path, '$'))
+ return path;
+
// ${VAR} is defined as
// $\{[A-Za-z_][A-Za-z_0-9]*\}
static string const envvar_br = "[$]\\{([A-Za-z_][A-Za-z_0-9]*)\\}";
@@ -702,14 +706,23 @@ string const replaceEnvironmentPath(string const & path)
string result = path;
while (1) {
smatch what;
+ bool brackets = true;
if (!regex_match(result, what, envvar_br_re)) {
+ brackets = false;
if (!regex_match(result, what, envvar_re))
break;
}
string env_var = getEnv(what.str(2));
+ if (env_var.empty()) {
+ // temporarily use escape (0x1B) in place of $
+ if (brackets)
+ env_var = "\e{" + what.str(2) + '}';
+ else
+ env_var = "\e" + what.str(2);
+ }
result = what.str(1) + env_var + what.str(3);
}
- return result;
+ return subst(result, '\e', '$');
} catch (exception const & e) {
LYXERR0("Something is very wrong: " << e.what());
return path;
--
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