From 24281f1506de2ae0815b2eaa82bb892d2ca0a2c9 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sun, 22 Feb 2009 13:15:52 +0100
Subject: [PATCH] Handle empty strings correctly.

---
 ChangeLog                          | 17 +++++++++++++++++
 lib/uninorm/u-normalize-internal.h | 23 +++++++++++++++++++++++
 tests/uninorm/test-u16-nfc.c       |  3 +++
 tests/uninorm/test-u16-nfd.c       |  3 +++
 tests/uninorm/test-u16-nfkc.c      |  3 +++
 tests/uninorm/test-u16-nfkd.c      |  3 +++
 tests/uninorm/test-u32-nfc.c       |  3 +++
 tests/uninorm/test-u32-nfd.c       |  3 +++
 tests/uninorm/test-u32-nfkc.c      |  3 +++
 tests/uninorm/test-u32-nfkd.c      |  3 +++
 tests/uninorm/test-u8-nfc.c        |  3 +++
 tests/uninorm/test-u8-nfd.c        |  3 +++
 tests/uninorm/test-u8-nfkc.c       |  3 +++
 tests/uninorm/test-u8-nfkd.c       |  3 +++
 14 files changed, 76 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 43b2c8f0b..4a07193d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2009-02-22  Bruno Haible  <bruno@clisp.org>
+
+	* lib/uninorm/u-normalize-internal.h (FUNC): At the end, handle
+	zero-length results and shrink excess allocated memory.
+	* tests/uninorm/test-u8-nfc.c (test_u8_nfc): Check empty string result.
+	* tests/uninorm/test-u8-nfd.c (test_u8_nfd): Likewise.
+	* tests/uninorm/test-u8-nfkc.c (test_u8_nfkc): Likewise.
+	* tests/uninorm/test-u8-nfkd.c (test_u8_nfkd): Likewise.
+	* tests/uninorm/test-u16-nfc.c (test_u16_nfc): Likewise.
+	* tests/uninorm/test-u16-nfd.c (test_u16_nfd): Likewise.
+	* tests/uninorm/test-u16-nfkc.c (test_u16_nfkc): Likewise.
+	* tests/uninorm/test-u16-nfkd.c (test_u16_nfkd): Likewise.
+	* tests/uninorm/test-u32-nfc.c (test_u32_nfc): Likewise.
+	* tests/uninorm/test-u32-nfd.c (test_u32_nfd): Likewise.
+	* tests/uninorm/test-u32-nfkc.c (test_u32_nfkc): Likewise.
+	* tests/uninorm/test-u32-nfkd.c (test_u32_nfkd): Likewise.
+
 2009-02-21  Bruno Haible  <bruno@clisp.org>
 
 	* doc/gnulib.texi: Include safe-alloc.texi earlier.
diff --git a/lib/uninorm/u-normalize-internal.h b/lib/uninorm/u-normalize-internal.h
index 7dc83ad9d..70c325513 100644
--- a/lib/uninorm/u-normalize-internal.h
+++ b/lib/uninorm/u-normalize-internal.h
@@ -331,6 +331,29 @@ FUNC (uninorm_t nf, const UNIT *s, size_t n,
       }
   }
 
+  if (length == 0)
+    {
+      if (result == NULL)
+	{
+	  /* Return a non-NULL value.  NULL means error.  */
+	  result = (UNIT *) malloc (1);
+	  if (result == NULL)
+	    {
+	      errno = ENOMEM;
+	      goto fail;
+	    }
+	}
+    }
+  else if (result != resultbuf && length < allocated)
+    {
+      /* Shrink the allocated memory if possible.  */
+      UNIT *memory;
+
+      memory = (UNIT *) realloc (result, length * sizeof (UNIT));
+      if (memory != NULL)
+	result = memory;
+    }
+
   if (sortbuf_count > 0)
     abort ();
   if (sortbuf != sortbuf_preallocated)
diff --git a/tests/uninorm/test-u16-nfc.c b/tests/uninorm/test-u16-nfc.c
index 397914c5f..70767df5a 100644
--- a/tests/uninorm/test-u16-nfc.c
+++ b/tests/uninorm/test-u16-nfc.c
@@ -103,6 +103,9 @@ check (const uint16_t *input, size_t input_length,
 void
 test_u16_nfc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint16_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u16-nfd.c b/tests/uninorm/test-u16-nfd.c
index 84499f0d3..161abd474 100644
--- a/tests/uninorm/test-u16-nfd.c
+++ b/tests/uninorm/test-u16-nfd.c
@@ -103,6 +103,9 @@ check (const uint16_t *input, size_t input_length,
 void
 test_u16_nfd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint16_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u16-nfkc.c b/tests/uninorm/test-u16-nfkc.c
index aa7bc2cee..df6480448 100644
--- a/tests/uninorm/test-u16-nfkc.c
+++ b/tests/uninorm/test-u16-nfkc.c
@@ -103,6 +103,9 @@ check (const uint16_t *input, size_t input_length,
 void
 test_u16_nfkc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint16_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u16-nfkd.c b/tests/uninorm/test-u16-nfkd.c
index 3cc1fac8f..587a704ae 100644
--- a/tests/uninorm/test-u16-nfkd.c
+++ b/tests/uninorm/test-u16-nfkd.c
@@ -103,6 +103,9 @@ check (const uint16_t *input, size_t input_length,
 void
 test_u16_nfkd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint16_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u32-nfc.c b/tests/uninorm/test-u32-nfc.c
index 0c7cd790f..3aafb96a8 100644
--- a/tests/uninorm/test-u32-nfc.c
+++ b/tests/uninorm/test-u32-nfc.c
@@ -103,6 +103,9 @@ check (const uint32_t *input, size_t input_length,
 void
 test_u32_nfc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint32_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u32-nfd.c b/tests/uninorm/test-u32-nfd.c
index 9aa820a3d..426ad9dd5 100644
--- a/tests/uninorm/test-u32-nfd.c
+++ b/tests/uninorm/test-u32-nfd.c
@@ -103,6 +103,9 @@ check (const uint32_t *input, size_t input_length,
 void
 test_u32_nfd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint32_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u32-nfkc.c b/tests/uninorm/test-u32-nfkc.c
index 0ef65f593..831e490a4 100644
--- a/tests/uninorm/test-u32-nfkc.c
+++ b/tests/uninorm/test-u32-nfkc.c
@@ -103,6 +103,9 @@ check (const uint32_t *input, size_t input_length,
 void
 test_u32_nfkc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint32_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u32-nfkd.c b/tests/uninorm/test-u32-nfkd.c
index 17768f74b..408c593b0 100644
--- a/tests/uninorm/test-u32-nfkd.c
+++ b/tests/uninorm/test-u32-nfkd.c
@@ -103,6 +103,9 @@ check (const uint32_t *input, size_t input_length,
 void
 test_u32_nfkd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint32_t input[]    = { 0x0020 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u8-nfc.c b/tests/uninorm/test-u8-nfc.c
index 0e1915708..5a86e59f2 100644
--- a/tests/uninorm/test-u8-nfc.c
+++ b/tests/uninorm/test-u8-nfc.c
@@ -103,6 +103,9 @@ check (const uint8_t *input, size_t input_length,
 void
 test_u8_nfc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint8_t input[]    = { 0x20 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u8-nfd.c b/tests/uninorm/test-u8-nfd.c
index 9dfde02c2..2338e8f8f 100644
--- a/tests/uninorm/test-u8-nfd.c
+++ b/tests/uninorm/test-u8-nfd.c
@@ -103,6 +103,9 @@ check (const uint8_t *input, size_t input_length,
 void
 test_u8_nfd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint8_t input[]    = { 0x20 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u8-nfkc.c b/tests/uninorm/test-u8-nfkc.c
index 6792e826d..1d9f0e1a9 100644
--- a/tests/uninorm/test-u8-nfkc.c
+++ b/tests/uninorm/test-u8-nfkc.c
@@ -103,6 +103,9 @@ check (const uint8_t *input, size_t input_length,
 void
 test_u8_nfkc (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint8_t input[]    = { 0x20 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
diff --git a/tests/uninorm/test-u8-nfkd.c b/tests/uninorm/test-u8-nfkd.c
index c2a2d1453..498f42e4b 100644
--- a/tests/uninorm/test-u8-nfkd.c
+++ b/tests/uninorm/test-u8-nfkd.c
@@ -103,6 +103,9 @@ check (const uint8_t *input, size_t input_length,
 void
 test_u8_nfkd (void)
 {
+  { /* Empty string.  */
+    ASSERT (check (NULL, 0, NULL, 0) == 0);
+  }
   { /* SPACE */
     static const uint8_t input[]    = { 0x20 };
     ASSERT (check (input, SIZEOF (input), input, SIZEOF (input)) == 0);
-- 
2.11.0