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-rw-r--r--compat/snprintf.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/compat/snprintf.c b/compat/snprintf.c
new file mode 100644
index 0000000..0b11688
--- /dev/null
+++ b/compat/snprintf.c
@@ -0,0 +1,69 @@
+#include "../git-compat-util.h"
+
+/*
+ * The size parameter specifies the available space, i.e. includes
+ * the trailing NUL byte; but Windows's vsnprintf uses the entire
+ * buffer and avoids the trailing NUL, should the buffer be exactly
+ * big enough for the result. Defining SNPRINTF_SIZE_CORR to 1 will
+ * therefore remove 1 byte from the reported buffer size, so we
+ * always have room for a trailing NUL byte.
+ */
+#ifndef SNPRINTF_SIZE_CORR
+#if defined(WIN32) && (!defined(__GNUC__) || __GNUC__ < 4) && (!defined(_MSC_VER) || _MSC_VER < 1900)
+#define SNPRINTF_SIZE_CORR 1
+#else
+#define SNPRINTF_SIZE_CORR 0
+#endif
+#endif
+
+#undef vsnprintf
+int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
+{
+ va_list cp;
+ char *s;
+ int ret = -1;
+
+ if (maxsize > 0) {
+ va_copy(cp, ap);
+ ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp);
+ va_end(cp);
+ if (ret == maxsize-1)
+ ret = -1;
+ /* Windows does not NUL-terminate if result fills buffer */
+ str[maxsize-1] = 0;
+ }
+ if (ret != -1)
+ return ret;
+
+ s = NULL;
+ if (maxsize < 128)
+ maxsize = 128;
+
+ while (ret == -1) {
+ maxsize *= 4;
+ str = realloc(s, maxsize);
+ if (! str)
+ break;
+ s = str;
+ va_copy(cp, ap);
+ ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp);
+ va_end(cp);
+ if (ret == maxsize-1)
+ ret = -1;
+ }
+ free(s);
+ return ret;
+}
+
+int git_snprintf(char *str, size_t maxsize, const char *format, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, format);
+ ret = git_vsnprintf(str, maxsize, format, ap);
+ va_end(ap);
+
+ return ret;
+}
+