ftell, ftello: Work around Solaris bug.

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/ftello.c b/lib/ftello.c
index a15e26bc15..098e36ae58 100644
--- a/lib/ftello.c
+++ b/lib/ftello.c
@@ -22,6 +22,8 @@
 /* Get lseek.  */
 #include <unistd.h>
 
+#include "stdio-impl.h"
+
 off_t
 ftello (FILE *fp)
 #undef ftello
@@ -36,6 +38,28 @@ ftello (FILE *fp)
     return -1;
 #endif
 
+#if FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE /* Solaris */
+  /* The Solaris stdio leaves the _IOREAD flag set after reading from a file
+     reaches EOF and the program then starts writing to the file.  ftello
+     gets confused by this.  */
+  if (fp_->_flag & _IOWRT)
+    {
+      off_t pos;
+
+      /* Call ftello nevertheless, for the side effects that it does on fp.  */
+      ftello (fp);
+
+      /* Compute the file position ourselves.  */
+      pos = llseek (fileno (fp), (off_t) 0, SEEK_CUR);
+      if (pos >= 0)
+        {
+          if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL)
+            pos += fp_->_ptr - fp_->_base;
+        }
+      return pos;
+    }
+#endif
+
 #if defined __SL64 && defined __SCLE /* Cygwin */
   if ((fp->_flags & __SL64) == 0)
     {