Fix error logged for send failure

[exim.git] / src / src / debug.c

diff --git a/src/src/debug.c b/src/src/debug.c
index 8bf4aedd9e2c7b79fb99b83af7c5827460cdc92a..8f9359b15837b9702a9e6616d3cd583bdd21e6d5 100644 (file)
--- a/src/src/debug.c
+++ b/src/src/debug.c
@@ -30,7 +30,7 @@ static uschar tree_printline[tree_printlinesize];
 
 Arguments:
   p          tree node
-  pos        amount of indenting & vertical bars to pring
+  pos        amount of indenting & vertical bars to print
   barswitch  if TRUE print | at the pos value
 
 Returns:     nothing
@@ -143,7 +143,8 @@ If debug_pid is nonzero, print the pid at the start of each line. This is for
 tidier output when running parallel remote deliveries with debugging turned on.
 Must do the whole thing with a single printf and flush, as otherwise output may
 get interleaved. Since some calls to debug_printf() don't end with newline,
-we save up the text until we do get the newline. */
+we save up the text until we do get the newline.
+Take care to not disturb errno. */
 
 void
 debug_printf(const char *format, ...)
@@ -157,7 +158,9 @@ va_end(ap);
 void
 debug_vprintf(const char *format, va_list ap)
 {
-if (debug_file == NULL) return;
+int save_errno = errno;
+
+if (!debug_file) return;
 
 /* Various things can be inserted at the start of a line. Don't use the
 tod_stamp() function for the timestamp, because that will overwrite the
@@ -235,6 +238,7 @@ if (debug_ptr[-1] == '\n')
   debug_ptr = debug_buffer;
   debug_prefix_length = 0;
   }
+errno = save_errno;
 }
 
 /* End of debug.c */