Read GSS configuration files with mtime 0

There is at least one case (with flatpaks) where configuration files
in the special read-only /etc all have an mtime of 0.  Using an
initial last modified time of 0 in g_initialize.c causes these files
to never be read.

Change the initial high value to the be the "invalid" value
(time_t)-1.  Since the C and POSIX standards do not require time_t to
be signed, special-case the checks in load_if_changed() and
updateMechList() to treat all mod times as newer than -1.

[ghudson@mit.edu: edited commit message; slightly modified approach]

ticket: 9060 (new)
target_version: 1.20
tags: pullup

diff --git a/src/lib/gssapi/mechglue/g_initialize.c b/src/lib/gssapi/mechglue/g_initialize.c
index b26262d69239b862c2676a7f11d7e488aef891a6..22f6c615c1f61e55b9bf0c09d432206c4f545ae4 100644 (file)
--- a/src/lib/gssapi/mechglue/g_initialize.c
+++ b/src/lib/gssapi/mechglue/g_initialize.c
@@ -93,7 +93,7 @@ static void free_mechSet(void);
 static gss_mech_info g_mechList = NULL;
 static gss_mech_info g_mechListTail = NULL;
 static k5_mutex_t g_mechListLock = K5_MUTEX_PARTIAL_INITIALIZER;
-static time_t g_confFileModTime = (time_t)0;
+static time_t g_confFileModTime = (time_t)-1;
 static time_t g_confLastCall = (time_t)0;
 
 static gss_OID_set_desc g_mechSet = { 0, NULL };
@@ -469,9 +469,9 @@ load_if_changed(const char *pathname, time_t last, time_t *highest)
        mtime = check_link_mtime(pathname, &mtime);
        if (mtime == (time_t)-1)
                return;
-       if (mtime > *highest)
+       if (mtime > *highest || *highest == (time_t)-1)
                *highest = mtime;
-       if (mtime > last)
+       if (mtime > last || last == (time_t)-1)
                loadConfigFile(pathname);
 }
 
@@ -482,7 +482,7 @@ static void
 loadConfigFiles()
 {
        glob_t globbuf;
-       time_t highest = 0, now;
+       time_t highest = (time_t)-1, now;
        char **path;
        const char *val;
 
@@ -522,7 +522,8 @@ updateMechList(void)
 
 #if defined(_WIN32)
        time_t lastConfModTime = getRegConfigModTime(MECH_KEY);
-       if (g_confFileModTime >= lastConfModTime)
+       if (g_confFileModTime >= lastConfModTime &&
+           g_confFileModTime != (time_t)-1)
                return;
        g_confFileModTime = lastConfModTime;
        loadConfigFromRegistry(HKEY_CURRENT_USER, MECH_KEY);