Fixing a typo in the record API causing segfaults, replacing localtime with thread-safe variant

Author: wberube

src/http_post.c

@@ -21,7 +21,7 @@ int http_post_send(hal_jpegdata *jpeg) {
         {
             time_t timer;
             time(&timer);
-            struct tm *tm_info = localtime(&timer);
+            struct tm tm_buf, *tm_info = localtime_r(&timer, &tm_buf);
             size_t time_len = strftime(
                 time_url, sizeof(time_url), app_config.http_post_url, tm_info);
             time_url[time_len++] = 0;

src/record.c

@@ -52,7 +52,7 @@ void record_start(void) {
         recordPath[sizeof(recordPath) - 1] = '\0';
     } else {
         char tempName[160];
-        struct tm *tm_info = localtime(&recordStartTime);
+        struct tm tm_buf, *tm_info = localtime_r(&recordStartTime, &tm_buf);
         sprintf(tempName, "recording_%s.mp4", timefmt);
         strftime(recordPath, sizeof(recordPath), tempName, tm_info);
     }

src/region.c

@@ -87,12 +87,12 @@ void region_fill_formatted(char* str) {
             ipos++;
             char s[64];
             time_t t = time(NULL);
-            struct tm *tm;
+            struct tm tm_buf, *tm_info;
             if (str[ipos + 1] == 'u') {
                 ipos++;
-                tm = gmtime(&t);
-            } else tm = localtime(&t);
-            strftime(s, 64, timefmt, tm);
+                tm_info = gmtime(&t);
+            } else tm_info = localtime_r(&t, &tm_buf);
+            strftime(s, 64, timefmt, tm_info);
             strcat(out, s);
             opos += strlen(s);
         }

src/server.c

@@ -1307,9 +1307,9 @@ void respond_request(http_request_t *req) {
                     record_stop();
             }
         }
-        struct tm *start = localtime(&recordStartTime);
+        struct tm tm_buf, *tm_info = localtime_r(&recordStartTime, &tm_buf);
         char start_time[64];
-        strftime(start_time, sizeof(start_time), "%Y-%m-%dT%H:%M:%SZ", start);
+        strftime(start_time, sizeof(start_time), "%Y-%m-%dT%H:%M:%SZ", tm_info);
 
         respLen = sprintf(response,
             "HTTP/1.1 200 OK\r\n"
@@ -1318,7 +1318,7 @@ void respond_request(http_request_t *req) {
             "\r\n"
             "{\"recording\":%s,\"start_time\":\"%s\",\"continuous\":\"%s\",\"path\":\"%s\","
             "\"filename\":\"%s\",\"segment_duration\":%d,\"segment_size\":%d}",
-                recordOn ? "true" : "false", recordStartTime, app_config.record_continuous ? "true" : "false",
+                recordOn ? "true" : "false", start_time, app_config.record_continuous ? "true" : "false",
                 app_config.record_path, app_config.record_filename, 
                 app_config.record_segment_duration, app_config.record_segment_size);
         send_and_close(req->clntFd, response, respLen);