X-Git-Url: https://ruderich.org/simon/gitweb/?p=coloredstderr%2Fcoloredstderr.git;a=blobdiff_plain;f=src%2Fdebug.h;h=b15695d068b18ddac26720cc3d909600232a78a0;hp=aebd88c29342815c8f6773aa08f81068f2bb999b;hb=8a65b4486febf00e3fad5bafc3773a811e675a4c;hpb=06f483dbeece72fa46fe43700b6e01279c92c916

diff --git a/src/debug.h b/src/debug.h
index aebd88c..b15695d 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -1,7 +1,7 @@
 /*
  * Debug functions.
  *
- * Copyright (C) 2013  Simon Ruderich
+ * Copyright (C) 2013-2015  Simon Ruderich
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -24,8 +24,10 @@ static void debug_write(int fd, int first_call, char const *format, va_list ap)
     char buffer[1024];
 
     int written = vsnprintf(buffer, sizeof(buffer), format, ap);
+    if (written < 0) {
+        return; /* shouldn't happen */
     /* Overflow. */
-    if ((size_t)written >= sizeof(buffer)) {
+    } else if ((size_t)written >= sizeof(buffer)) {
         written = sizeof(buffer) - 1;
     }
 
@@ -34,20 +36,24 @@ static void debug_write(int fd, int first_call, char const *format, va_list ap)
     DLSYM_FUNCTION(real_close, "close");
 
     if (first_call) {
-        char nl = '\n';
+        char const nl = '\n';
         real_write(fd, &nl, 1);
     }
     real_write(fd, buffer, (size_t)written);
     real_close(fd);
 }
 
+#ifdef DEBUG
 static void debug(char const *format, ...) {
     va_list ap;
 
+    int saved_errno = errno;
+
     /* If the file doesn't exist, do nothing. Prevents writing log files in
      * unexpected places. The user must create the file manually. */
     int fd = open(DEBUG_FILE, O_WRONLY | O_APPEND);
     if (fd == -1) {
+        errno = saved_errno;
         return;
     }
 
@@ -57,13 +63,19 @@ static void debug(char const *format, ...) {
     va_start(ap, format);
     debug_write(fd, call_count == 1, format, ap);
     va_end(ap);
+
+    errno = saved_errno;
 }
+#endif
 
 static void warning(char const *format, ...) {
     va_list ap;
 
+    int saved_errno = errno;
+
     char const *home = getenv("HOME");
     if (!home) {
+        errno = saved_errno;
         return;
     }
 
@@ -75,6 +87,7 @@ static void warning(char const *format, ...) {
     /* Create the warning file if it doesn't exist yet. */
     int fd = open(path, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
     if (fd == -1) {
+        errno = saved_errno;
         return;
     }
 
@@ -84,6 +97,8 @@ static void warning(char const *format, ...) {
     va_start(ap, format);
     debug_write(fd, call_count == 1, format, ap);
     va_end(ap);
+
+    errno = saved_errno;
 }
 
 #endif