--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-28  Paul Eggert  <eggert@cs.ucla.edu>
+
+	extern-inline: work around bug in Sun c99
+	* m4/extern-inline.m4 (_GL_INLINE, _GL_EXTERN_INLINE):
+	Work around bug in Sun C 5.12 c99's implementation of 'inline'.
+
 2013-04-27  Paul Eggert  <eggert@cs.ucla.edu>
 
 	qacl: new module, broken out from the acl module

--- a/m4/extern-inline.m4
+++ b/m4/extern-inline.m4
@@ -21,13 +21,21 @@
    Suppress extern inline with HP-UX cc, as it appears to be broken; see
    <http://lists.gnu.org/archive/html/bug-texinfo/2013-02/msg00030.html>.
 
-   Suppress the use of extern inline on Apple's platforms,
-   as Libc-825.25 (2012-09-19) is incompatible with it; see
+   Suppress extern inline with Sun C in standards-conformance mode, as it
+   mishandles inline functions that call each other.  E.g., for 'inline void f
+   (void) { } inline void g (void) { f (); }', c99 incorrectly complains
+   'reference to static identifier "f" in extern inline function'.
+   This bug was observed with Sun C 5.12 SunOS_i386 2011/11/16.
+
+   Suppress the use of extern inline on Apple's platforms, as Libc at least
+   through Libc-825.26 (2013-04-09) is incompatible with it; see, e.g.,
    <http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html>.
    Perhaps Apple will fix this some day.  */
 #if ((__GNUC__ \
       ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
-      : 199901L <= __STDC_VERSION__ && !defined __HP_cc) \
+      : (199901L <= __STDC_VERSION__ \
+         && !defined __HP_cc \
+         && !(defined __SUNPRO_C && __STDC__))) \
      && !defined __APPLE__)
 # define _GL_INLINE inline
 # define _GL_EXTERN_INLINE extern inline