# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1552086107 -3600
# Node ID 8da9577294dafd839a9561ab164efa95c6def786
# Parent  5f58d2ac35ea2fc31ccc90cb6d21b8327ce30986
unistr/*, uniconv/*: Fix undefined behaviour.

Reported by Jeffrey Walton <noloader@gmail.com>.

* lib/unistr/u-cpy.h (FUNC): Don't invoke memcpy with a zero size.
* lib/unistr/u-cpy-alloc.h (FUNC): Likewise.
* lib/uniconv/u8-conv-from-enc.c (u8_conv_from_encoding): Likewise.
* lib/uniconv/u8-conv-to-enc.c (u8_conv_to_encoding): Likewise.

diff -r 5f58d2ac35ea -r 8da9577294da ChangeLog
--- a/ChangeLog	Fri Mar 08 20:38:22 2019 +0100
+++ b/ChangeLog	Sat Mar 09 00:01:47 2019 +0100
@@ -1,3 +1,12 @@
+2019-03-08  Bruno Haible  <bruno@clisp.org>
+
+	unistr/*, uniconv/*: Fix undefined behaviour.
+	Reported by Jeffrey Walton <noloader@gmail.com>.
+	* lib/unistr/u-cpy.h (FUNC): Don't invoke memcpy with a zero size.
+	* lib/unistr/u-cpy-alloc.h (FUNC): Likewise.
+	* lib/uniconv/u8-conv-from-enc.c (u8_conv_from_encoding): Likewise.
+	* lib/uniconv/u8-conv-to-enc.c (u8_conv_to_encoding): Likewise.
+
 2019-03-08  Bruno Haible  <bruno@clisp.org>
 
 	unistr/u8-cmp: Fix undefined behaviour.
diff -r 5f58d2ac35ea -r 8da9577294da lib/uniconv/u8-conv-from-enc.c
--- a/lib/uniconv/u8-conv-from-enc.c	Fri Mar 08 20:38:22 2019 +0100
+++ b/lib/uniconv/u8-conv-from-enc.c	Sat Mar 09 00:01:47 2019 +0100
@@ -77,7 +77,8 @@
             }
         }
 
-      memcpy ((char *) result, src, srclen);
+      if (srclen > 0)
+        memcpy ((char *) result, src, srclen);
       *lengthp = srclen;
       return result;
     }
diff -r 5f58d2ac35ea -r 8da9577294da lib/uniconv/u8-conv-to-enc.c
--- a/lib/uniconv/u8-conv-to-enc.c	Fri Mar 08 20:38:22 2019 +0100
+++ b/lib/uniconv/u8-conv-to-enc.c	Sat Mar 09 00:01:47 2019 +0100
@@ -60,7 +60,8 @@
             }
         }
 
-      memcpy (result, (const char *) src, srclen);
+      if (srclen > 0)
+        memcpy (result, (const char *) src, srclen);
       *lengthp = srclen;
       return result;
     }
diff -r 5f58d2ac35ea -r 8da9577294da lib/unistr/u-cpy-alloc.h
--- a/lib/unistr/u-cpy-alloc.h	Fri Mar 08 20:38:22 2019 +0100
+++ b/lib/unistr/u-cpy-alloc.h	Sat Mar 09 00:01:47 2019 +0100
@@ -33,7 +33,8 @@
       for (; n > 0; n--)
         *destptr++ = *s++;
 #else
-      memcpy ((char *) dest, (const char *) s, n * sizeof (UNIT));
+      if (n > 0)
+        memcpy ((char *) dest, (const char *) s, n * sizeof (UNIT));
 #endif
     }
   return dest;
diff -r 5f58d2ac35ea -r 8da9577294da lib/unistr/u-cpy.h
--- a/lib/unistr/u-cpy.h	Fri Mar 08 20:38:22 2019 +0100
+++ b/lib/unistr/u-cpy.h	Sat Mar 09 00:01:47 2019 +0100
@@ -26,7 +26,8 @@
   for (; n > 0; n--)
     *destptr++ = *src++;
 #else
-  memcpy ((char *) dest, (const char *) src, n * sizeof (UNIT));
+  if (n > 0)
+    memcpy ((char *) dest, (const char *) src, n * sizeof (UNIT));
 #endif
   return dest;
 }