Merge branch 'jk/strbuf-vaddf'

* jk/strbuf-vaddf:
  compat: fall back on __va_copy if available
  strbuf: add strbuf_vaddf
  compat: provide a fallback va_copy definition

diff --combined git-compat-util.h
index bf947b1ec361aafeef58d43ef8eae979699b35ac,f4cb0a9b0182da5366249ce6e53e24773fd2b174..49b50eec86828066c90b6165c35ec21cb51e85ce
--- 1/git-compat-util.h
--- 2/git-compat-util.h
+++ b/git-compat-util.h
@@@ -214,10 -214,7 +214,10 @@@ extern char *gitbasename(char *)
  #define is_dir_sep(c) ((c) == '/')
  #endif
  
 -#ifdef __GNUC__
 +#if __HP_cc >= 61000
 +#define NORETURN __attribute__((noreturn))
 +#define NORETURN_PTR
 +#elif defined(__GNUC__)
  #define NORETURN __attribute__((__noreturn__))
  #define NORETURN_PTR __attribute__((__noreturn__))
  #elif defined(_MSC_VER)
@@@ -538,6 -535,19 +538,19 @@@ void git_qsort(void *base, size_t nmemb
  #define fstat_is_reliable() 1
  #endif
  
+ #ifndef va_copy
+ /*
+  * Since an obvious implementation of va_list would be to make it a
+  * pointer into the stack frame, a simple assignment will work on
+  * many systems.  But let's try to be more portable.
+  */
+ #ifdef __va_copy
+ #define va_copy(dst, src) __va_copy(dst, src)
+ #else
+ #define va_copy(dst, src) ((dst) = (src))
+ #endif
+ #endif
+ 
  /*
   * Preserves errno, prints a message, but gives no warning for ENOENT.
   * Always returns the return value of unlink(2).