Work around some potential problems with thread-unsafe getenv

I have seen at least one failure of one of our unoapi tests where soffice.bin
crashed in getenv(3).  This patch is just a drop in the ocean, though.

Change-Id: Iac8a2283b0a62e4fa95a0d063c1676af6c2390be

4 files changed, 42 insertions, 27 deletions

diff --git a/sal/osl/all/log.cxx b/sal/osl/all/log.cxx
index bac0e9313919..934d88aa0a3e 100644
--- a/sal/osl/all/log.cxx
+++ b/sal/osl/all/log.cxx
@@ -38,6 +38,7 @@
 #include <sstream>
 
 #include <stdio.h> // vsnprintf
+#include <string.h> // strdup
 
 #include "osl/thread.hxx"
 #include "rtl/string.h"
@@ -82,14 +83,24 @@ char const * toString(sal_detail_LogLevel level) {
     }
 }
 
+// getenv is not thread safe, so minimize use of result:
+char const * getEnvironmentVariable() {
+    char const * p1 = std::getenv("SAL_LOG");
+    if (p1 == 0) {
+        return "+WARN";
+    }
+    char const * p2 = strdup(p1); // leaked
+    if (p2 == 0) {
+        std::abort(); // cannot do much here
+    }
+    return p2;
+}
+
 bool report(sal_detail_LogLevel level, char const * area) {
     if (level == SAL_DETAIL_LOG_LEVEL_DEBUG)
         return true;
     assert(area != 0);
-    char const * env = std::getenv("SAL_LOG");
-    if (env == 0) {
-        env = "+WARN";
-    }
+    static char const * env = getEnvironmentVariable();
     std::size_t areaLen = std::strlen(area);
     enum Sense { POSITIVE = 0, NEGATIVE = 1 };
     std::size_t senseLen[2] = { 0, 1 };
diff --git a/sal/osl/unx/diagnose.cxx b/sal/osl/unx/diagnose.cxx
index 38f11e07896b..8c289f23164a 100644
--- a/sal/osl/unx/diagnose.cxx
+++ b/sal/osl/unx/diagnose.cxx
@@ -209,6 +209,17 @@ static void osl_diagnose_backtrace_Impl (oslDebugMessageFunc f)
 /************************************************************************/
 /* osl_assertFailedLine */
 /************************************************************************/
+
+namespace {
+
+// getenv is not thread safe, so minimize use of result:
+bool isEnv(char const * name) {
+    char * p = getenv(name);
+    return p != NULL && *p != '\0';
+}
+
+}
+
 sal_Bool SAL_CALL osl_assertFailedLine (
     const sal_Char* pszFileName,
     sal_Int32       nLine,
@@ -219,9 +230,9 @@ sal_Bool SAL_CALL osl_assertFailedLine (
 
     // after reporting the assertion, abort if told so by SAL_DIAGNOSE_ABORT, but *not* if
     // assertions are routed to some external instance
-    char const * env = getenv( "SAL_DIAGNOSE_ABORT" );
-    char const * envBacktrace = getenv( "SAL_DIAGNOSE_BACKTRACE" );
-    sal_Bool const doAbort = ( ( env != NULL ) && ( *env != '\0' ) && ( f == NULL ) );
+    static bool envAbort = isEnv( "SAL_DIAGNOSE_ABORT" );
+    static bool envBacktrace = isEnv( "SAL_DIAGNOSE_BACKTRACE" );
+    sal_Bool const doAbort = envAbort && f == NULL;
 
     /* If there's a callback for detailed messages, use it */
     if ( g_pDetailedDebugMessageFunc != NULL )
@@ -251,7 +262,7 @@ sal_Bool SAL_CALL osl_assertFailedLine (
     OSL_DIAGNOSE_OUTPUTMESSAGE(f, szMessage);
 
     /* should we output backtrace? */
-    if( envBacktrace != NULL && *envBacktrace != '\0' )
+    if( envBacktrace )
         osl_diagnose_backtrace_Impl(f);
 
     /* release lock and leave */
diff --git a/sal/osl/unx/file.cxx b/sal/osl/unx/file.cxx
index 536e1bf8a8b8..699cb311c7a9 100644
--- a/sal/osl/unx/file.cxx
+++ b/sal/osl/unx/file.cxx
@@ -831,27 +831,19 @@ static int osl_file_adjustLockFlags (const char * path, int flags)
 /****************************************************************************
  *  osl_file_queryLocking
  ***************************************************************************/
-struct Locking_Impl
+static bool osl_file_queryLocking (sal_uInt32 uFlags)
 {
-    int m_enabled;
-    Locking_Impl() : m_enabled(0)
+#if !defined HAVE_O_EXLOCK
+    if (!(uFlags & osl_File_OpenFlag_NoLock)
+        && ((uFlags & osl_File_OpenFlag_Write)
+            || (uFlags & osl_File_OpenFlag_Create)))
     {
-#ifndef HAVE_O_EXLOCK
-        m_enabled = (getenv("SAL_ENABLE_FILE_LOCKING") != 0);
-#endif /* HAVE_O_EXLOCK */
-    }
-};
-static int osl_file_queryLocking (sal_uInt32 uFlags)
-{
-    if (!(uFlags & osl_File_OpenFlag_NoLock))
-    {
-        if ((uFlags & osl_File_OpenFlag_Write) || (uFlags & osl_File_OpenFlag_Create))
-        {
-            static Locking_Impl g_locking;
-            return (g_locking.m_enabled != 0);
-        }
+        static bool enabled = getenv("SAL_ENABLE_FILE_LOCKING") != 0;
+            // getenv is not thread safe, so minimize use of result
+        return enabled;
     }
-    return 0;
+#endif
+    return false;
 }
 
 #ifdef UNX
diff --git a/sal/osl/unx/file_url.cxx b/sal/osl/unx/file_url.cxx
index 7addb8e00d24..b58251577d43 100644
--- a/sal/osl/unx/file_url.cxx
+++ b/sal/osl/unx/file_url.cxx
@@ -633,7 +633,6 @@ oslFileError osl_getAbsoluteFileURL(rtl_uString*  ustrBaseDirURL, rtl_uString* u
 {
     FileBase::RC  rc;
     rtl::OUString unresolved_path;
-    static char *allow_symlinks = getenv( "SAL_ALLOW_LINKOO_SYMLINKS" );
 
     rc = FileBase::getSystemPathFromFileURL(rtl::OUString(ustrRelativeURL), unresolved_path);
 
@@ -656,6 +655,8 @@ oslFileError osl_getAbsoluteFileURL(rtl_uString*  ustrBaseDirURL, rtl_uString* u
 
     rtl::OUString resolved_path;
 
+    static bool allow_symlinks = getenv("SAL_ALLOW_LINKOO_SYMLINKS") != 0;
+        // getenv is not thread safe, so minimize use of result
     if (!allow_symlinks)
     {
         rc = (FileBase::RC) osl_getAbsoluteFileURL_impl_(unresolved_path, resolved_path);