From b5b0da78e56e474051438717fdddcc144c011a63 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 13:33:12 +0530
Subject: [PATCH 01/23] gh-127740: For odd-length input to bytes.fromhex(...)
 change the error message to  ValueError: fromhex() arg must be of even length

---
 Lib/test/test_bytes.py |  5 +++++
 Objects/bytesobject.c  | 15 ++++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 9e1985bb3a7639..576499517b11c7 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -459,6 +459,11 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '\x00')
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
+        # For odd number of character(s)
+        with self.assertRaises(ValueError) as cm:
+            self.type2test.fromhex("a")
+        self.assertIn("fromhex() arg must be of even length", str(cm.exception))
+
         for data, pos in (
             # invalid first hexadecimal character
             ('12 x4 56', 3),
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 8c7651f0f3aa45..b076d922e2da71 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2490,7 +2490,7 @@ PyObject*
 _PyBytes_FromHex(PyObject *string, int use_bytearray)
 {
     char *buf;
-    Py_ssize_t hexlen, invalid_char;
+    Py_ssize_t hexlen, invalid_char,real_len=0;
     unsigned int top, bot;
     const Py_UCS1 *str, *end;
     _PyBytesWriter writer;
@@ -2516,6 +2516,19 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     }
 
     assert(PyUnicode_KIND(string) == PyUnicode_1BYTE_KIND);
+
+    const Py_UCS1 *s = PyUnicode_1BYTE_DATA(string);
+    for (Py_ssize_t i = 0; i < hexlen; i++) {
+        if (!Py_ISSPACE(s[i])) {
+            real_len++;
+        }
+    }
+    if (real_len % 2 != 0) {
+        PyErr_SetString(PyExc_ValueError,
+                       "fromhex() arg must be of even length");
+        _PyBytesWriter_Dealloc(&writer);
+        return NULL;
+    }
     str = PyUnicode_1BYTE_DATA(string);
 
     /* This overestimates if there are spaces */

From 14b7d5eeff28bcadc0d9279aef53ed59eaed925d Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 13:36:01 +0530
Subject: [PATCH 02/23] Introduce space between variables

---
 Objects/bytesobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index b076d922e2da71..01b895a245e268 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2490,7 +2490,7 @@ PyObject*
 _PyBytes_FromHex(PyObject *string, int use_bytearray)
 {
     char *buf;
-    Py_ssize_t hexlen, invalid_char,real_len=0;
+    Py_ssize_t hexlen, invalid_char, real_len=0;
     unsigned int top, bot;
     const Py_UCS1 *str, *end;
     _PyBytesWriter writer;

From f3bfe8537c59f6284d92b186f28c9c1304cfcc5f Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 14:13:34 +0530
Subject: [PATCH 03/23] gh-127740: Improve code, consolidate two variables into
 one

---
 Objects/bytesobject.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 01b895a245e268..9dac36933d4e81 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2516,10 +2516,9 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     }
 
     assert(PyUnicode_KIND(string) == PyUnicode_1BYTE_KIND);
-
-    const Py_UCS1 *s = PyUnicode_1BYTE_DATA(string);
+    str = PyUnicode_1BYTE_DATA(string);
     for (Py_ssize_t i = 0; i < hexlen; i++) {
-        if (!Py_ISSPACE(s[i])) {
+        if (!Py_ISSPACE(str[i])) {
             real_len++;
         }
     }
@@ -2529,7 +2528,6 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         _PyBytesWriter_Dealloc(&writer);
         return NULL;
     }
-    str = PyUnicode_1BYTE_DATA(string);
 
     /* This overestimates if there are spaces */
     buf = _PyBytesWriter_Alloc(&writer, hexlen / 2);

From 5a55e24dbe9d63f1b23a2cfe910add02f42802cc Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 16:14:26 +0530
Subject: [PATCH 04/23] Check the logic inside of the loop, instead of checking
 eagerly

---
 Objects/bytesobject.c | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 9dac36933d4e81..0f123f2d48837a 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2517,17 +2517,6 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
 
     assert(PyUnicode_KIND(string) == PyUnicode_1BYTE_KIND);
     str = PyUnicode_1BYTE_DATA(string);
-    for (Py_ssize_t i = 0; i < hexlen; i++) {
-        if (!Py_ISSPACE(str[i])) {
-            real_len++;
-        }
-    }
-    if (real_len % 2 != 0) {
-        PyErr_SetString(PyExc_ValueError,
-                       "fromhex() arg must be of even length");
-        _PyBytesWriter_Dealloc(&writer);
-        return NULL;
-    }
 
     /* This overestimates if there are spaces */
     buf = _PyBytesWriter_Alloc(&writer, hexlen / 2);
@@ -2537,14 +2526,13 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     end = str + hexlen;
     while (str < end) {
         /* skip over spaces in the input */
-        if (Py_ISSPACE(*str)) {
-            do {
-                str++;
-            } while (Py_ISSPACE(*str));
-            if (str >= end)
-                break;
+        while (str < end && Py_ISSPACE(*str)) {
+            str++;
         }
+        if (str >= end)
+            break;
 
+        /* Check first hex digit */
         top = _PyLong_DigitValue[*str];
         if (top >= 16) {
             invalid_char = str - PyUnicode_1BYTE_DATA(string);
@@ -2552,6 +2540,15 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
+        /* Check if we have a second digit*/
+        if (str >= end || Py_ISSPACE(*str)) {
+            PyErr_SetString(PyExc_ValueError,
+                           "fromhex() arg must be of even length");
+            _PyBytesWriter_Dealloc(&writer);
+            return NULL;
+        }
+
+        /* Check second hex digit */
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
             invalid_char = str - PyUnicode_1BYTE_DATA(string);

From a3ba0e76f08b27db1ffde11fa418a9079599dcd1 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 16:15:39 +0530
Subject: [PATCH 05/23] Remove dead variable

---
 Objects/bytesobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 0f123f2d48837a..e8832e1bf7aad6 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2490,7 +2490,7 @@ PyObject*
 _PyBytes_FromHex(PyObject *string, int use_bytearray)
 {
     char *buf;
-    Py_ssize_t hexlen, invalid_char, real_len=0;
+    Py_ssize_t hexlen, invalid_char;
     unsigned int top, bot;
     const Py_UCS1 *str, *end;
     _PyBytesWriter writer;

From ee7947a21314e40d2e1ec4a84fd691a8e967aff3 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 16:29:43 +0530
Subject: [PATCH 06/23] Fix a bug in logic

---
 Objects/bytesobject.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index e8832e1bf7aad6..983eae6677d9ae 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2540,8 +2540,13 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
+        /* Skip spaces after first digit */
+        while (str < end && Py_ISSPACE(*str)) {
+            str++;
+        }
+
         /* Check if we have a second digit*/
-        if (str >= end || Py_ISSPACE(*str)) {
+        if (str >= end) {
             PyErr_SetString(PyExc_ValueError,
                            "fromhex() arg must be of even length");
             _PyBytesWriter_Dealloc(&writer);

From 879994e2a6bdd91c5e71910dc6242d2001be7505 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 16:34:16 +0530
Subject: [PATCH 07/23] Add some more tests

---
 Lib/test/test_bytes.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 576499517b11c7..92c455efdf5d8c 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,9 +460,10 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        with self.assertRaises(ValueError) as cm:
-            self.type2test.fromhex("a")
-        self.assertIn("fromhex() arg must be of even length", str(cm.exception))
+        for value in ("a", "a ", " a"," a ", "aaa", "aaa   ", "   aaa", "   aaa   "):
+            with self.assertRaises(ValueError) as cm:
+                self.type2test.fromhex(value)
+            self.assertIn("fromhex() arg must be of even length", str(cm.exception))
 
         for data, pos in (
             # invalid first hexadecimal character

From ad96b89811ee8a3502a4830a8518d6985ef649f2 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 16:40:43 +0530
Subject: [PATCH 08/23] Improve tests

---
 Lib/test/test_bytes.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 92c455efdf5d8c..5c45f9c50fc039 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,7 +460,7 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "aaa", "aaa   ", "   aaa", "   aaa   "):
+        for value in ("a", "a ", " a"," a ", "a a a", "a a a   ", "   a a a", "   a a a   "):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
             self.assertIn("fromhex() arg must be of even length", str(cm.exception))

From 95744bda2f16f290a8531fb693e3ca3c246a0ce5 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 17:37:26 +0530
Subject: [PATCH 09/23] Revert the change that is not necessary

---
 Objects/bytesobject.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 983eae6677d9ae..879f9af32b4612 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2526,11 +2526,13 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     end = str + hexlen;
     while (str < end) {
         /* skip over spaces in the input */
-        while (str < end && Py_ISSPACE(*str)) {
-            str++;
+        if (Py_ISSPACE(*str)) {
+            do {
+                str++;
+            } while (Py_ISSPACE(*str));
+            if (str >= end)
+                break;
         }
-        if (str >= end)
-            break;
 
         /* Check first hex digit */
         top = _PyLong_DigitValue[*str];

From 6929a4dd582f77ee36664f6c0b9ba41806183606 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 17:59:44 +0530
Subject: [PATCH 10/23] Move everthing to error labels

---
 Objects/bytesobject.c | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 879f9af32b4612..233c1c0c8b0df9 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2542,19 +2542,6 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
-        /* Skip spaces after first digit */
-        while (str < end && Py_ISSPACE(*str)) {
-            str++;
-        }
-
-        /* Check if we have a second digit*/
-        if (str >= end) {
-            PyErr_SetString(PyExc_ValueError,
-                           "fromhex() arg must be of even length");
-            _PyBytesWriter_Dealloc(&writer);
-            return NULL;
-        }
-
         /* Check second hex digit */
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
@@ -2569,9 +2556,15 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     return _PyBytesWriter_Finish(&writer, buf);
 
   error:
-    PyErr_Format(PyExc_ValueError,
-                 "non-hexadecimal number found in "
-                 "fromhex() arg at position %zd", invalid_char);
+    if (str >= end) {
+        PyErr_SetString(PyExc_ValueError,
+                        "fromhex() arg must be of even length");
+    }
+    else {
+        PyErr_Format(PyExc_ValueError,
+                     "non-hexadecimal number found in "
+                     "fromhex() arg at position %zd", invalid_char);
+    }
     _PyBytesWriter_Dealloc(&writer);
     return NULL;
 }

From aa6684bde1db471b3b580ed7b13b8b51720621b3 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 18:01:21 +0530
Subject: [PATCH 11/23] Remove comments

---
 Objects/bytesobject.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 233c1c0c8b0df9..fe0477ffa5ad06 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2534,7 +2534,6 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
                 break;
         }
 
-        /* Check first hex digit */
         top = _PyLong_DigitValue[*str];
         if (top >= 16) {
             invalid_char = str - PyUnicode_1BYTE_DATA(string);
@@ -2542,7 +2541,6 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
-        /* Check second hex digit */
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
             invalid_char = str - PyUnicode_1BYTE_DATA(string);

From bf3ace9a17cc32738467123bd4e22b3c40f55328 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 20:21:55 +0530
Subject: [PATCH 12/23] Add tests and update logic

---
 Lib/test/test_bytes.py |  2 +-
 Objects/bytesobject.c  | 20 +++++++++++---------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 5c45f9c50fc039..44efe45afc0dff 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,7 +460,7 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "a a a", "a a a   ", "   a a a", "   a a a   "):
+        for value in ("a", "a ", " a"," a ", "a a a", "aa a ", " aa a", " aaa "):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
             self.assertIn("fromhex() arg must be of even length", str(cm.exception))
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index fe0477ffa5ad06..30f232e2dbb231 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2541,6 +2541,14 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
+        /* Check if we have a second digit*/
+        if (str >= end) {
+            PyErr_SetString(PyExc_ValueError,
+                           "fromhex() arg must be of even length");
+            _PyBytesWriter_Dealloc(&writer);
+            return NULL;
+        }
+
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
             invalid_char = str - PyUnicode_1BYTE_DATA(string);
@@ -2554,15 +2562,9 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     return _PyBytesWriter_Finish(&writer, buf);
 
   error:
-    if (str >= end) {
-        PyErr_SetString(PyExc_ValueError,
-                        "fromhex() arg must be of even length");
-    }
-    else {
-        PyErr_Format(PyExc_ValueError,
-                     "non-hexadecimal number found in "
-                     "fromhex() arg at position %zd", invalid_char);
-    }
+    PyErr_Format(PyExc_ValueError,
+                 "non-hexadecimal number found in "
+                 "fromhex() arg at position %zd", invalid_char);
     _PyBytesWriter_Dealloc(&writer);
     return NULL;
 }

From 3588d181dc8c611a094397b754b2d6b830c7b0cc Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 20:29:46 +0530
Subject: [PATCH 13/23] Update tests

---
 Lib/test/test_bytes.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 44efe45afc0dff..400f99ca6810ba 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,7 +460,7 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "a a a", "aa a ", " aa a", " aaa "):
+        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa "):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
             self.assertIn("fromhex() arg must be of even length", str(cm.exception))

From 504f4edc0ad2214ad309235a9bd1909879de9bf0 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 20:38:55 +0530
Subject: [PATCH 14/23] Add tests and update logic

---
 Objects/bytesobject.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 30f232e2dbb231..832939e5535ae1 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2541,12 +2541,10 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
         }
         str++;
 
-        /* Check if we have a second digit*/
+        /* Check if we have a second digit */
         if (str >= end) {
-            PyErr_SetString(PyExc_ValueError,
-                           "fromhex() arg must be of even length");
-            _PyBytesWriter_Dealloc(&writer);
-            return NULL;
+            invalid_char = -2;
+            goto error;
         }
 
         bot = _PyLong_DigitValue[*str];
@@ -2562,9 +2560,14 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     return _PyBytesWriter_Finish(&writer, buf);
 
   error:
-    PyErr_Format(PyExc_ValueError,
-                 "non-hexadecimal number found in "
-                 "fromhex() arg at position %zd", invalid_char);
+    if (invalid_char == -2) {
+        PyErr_SetString(PyExc_ValueError,
+                        "fromhex() arg must be of even length");
+    } else {
+        PyErr_Format(PyExc_ValueError,
+                     "non-hexadecimal number found in "
+                     "fromhex() arg at position %zd", invalid_char);
+    }
     _PyBytesWriter_Dealloc(&writer);
     return NULL;
 }

From 7bab683e1ea5684f97b3e93bb669989afdebd6ac Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 20:51:27 +0530
Subject: [PATCH 15/23] Change the invalid_char value to -1

---
 Objects/bytesobject.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 832939e5535ae1..4f8a48c20c1f7a 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2543,7 +2543,7 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
 
         /* Check if we have a second digit */
         if (str >= end) {
-            invalid_char = -2;
+            invalid_char = -1;
             goto error;
         }
 
@@ -2560,7 +2560,7 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
     return _PyBytesWriter_Finish(&writer, buf);
 
   error:
-    if (invalid_char == -2) {
+    if (invalid_char == -1) {
         PyErr_SetString(PyExc_ValueError,
                         "fromhex() arg must be of even length");
     } else {

From 7c819c1bce974ba35d58d176455042b6bbb838e4 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Mon, 9 Dec 2024 20:58:19 +0530
Subject: [PATCH 16/23] Update test case

---
 Lib/test/test_bytes.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 400f99ca6810ba..c2fc13e8db3d5d 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,7 +460,7 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa "):
+        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa ",  " aa a "):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
             self.assertIn("fromhex() arg must be of even length", str(cm.exception))

From 862bfd578435b0c4d80fc5da0ddc1a628f964447 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 12:49:03 +0530
Subject: [PATCH 17/23] gh-127740: Improve error messages as suggested by
 @hauntsaninja

---
 Lib/test/test_bytes.py | 4 ++--
 Objects/bytesobject.c  | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index c2fc13e8db3d5d..d3331bbb932da8 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,10 +460,10 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa ",  " aa a "):
+        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa "):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
-            self.assertIn("fromhex() arg must be of even length", str(cm.exception))
+            self.assertIn("fromhex() arg must contain an even number of hexadecimal digits", str(cm.exception))
 
         for data, pos in (
             # invalid first hexadecimal character
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 4f8a48c20c1f7a..b59c414c7cbf81 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2562,7 +2562,7 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
   error:
     if (invalid_char == -1) {
         PyErr_SetString(PyExc_ValueError,
-                        "fromhex() arg must be of even length");
+                        "fromhex() arg must contain an even number of hexadecimal digits");
     } else {
         PyErr_Format(PyExc_ValueError,
                      "non-hexadecimal number found in "

From 6cc930541ccd73516086ee2574f63ec04030346e Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 13:10:41 +0530
Subject: [PATCH 18/23] Update test cases

---
 Lib/test/test_bytes.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index d3331bbb932da8..32cd178fa3b445 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -460,7 +460,7 @@ def test_fromhex(self):
         self.assertRaises(ValueError, self.type2test.fromhex, '12   \x00   34')
 
         # For odd number of character(s)
-        for value in ("a", "a ", " a"," a ", "aaa", "aaa ", " aaa", " aaa "):
+        for value in ("a", "aaa", "deadbee"):
             with self.assertRaises(ValueError) as cm:
                 self.type2test.fromhex(value)
             self.assertIn("fromhex() arg must contain an even number of hexadecimal digits", str(cm.exception))

From c34696e7268a97c29e3015a0f52cdf1d25c782ae Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 14:51:40 +0530
Subject: [PATCH 19/23] gh-127740: NULL at the end is mapped to 37

---
 Objects/bytesobject.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index b59c414c7cbf81..b5819dc88f7948 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2540,16 +2540,14 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
             goto error;
         }
         str++;
-
-        /* Check if we have a second digit */
-        if (str >= end) {
-            invalid_char = -1;
-            goto error;
-        }
-
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
-            invalid_char = str - PyUnicode_1BYTE_DATA(string);
+            /* NULL at the end of the string */
+            if (bot == 37){
+                invalid_char = -1;
+            } else {
+                invalid_char = str - PyUnicode_1BYTE_DATA(string);
+            }
             goto error;
         }
         str++;

From 82762db31f2beb85069f52f17ff46f59bf968552 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 14:53:13 +0530
Subject: [PATCH 20/23] gh-127740: Reintroduce the space back

---
 Objects/bytesobject.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index b5819dc88f7948..474a625143e9a7 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2540,6 +2540,7 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
             goto error;
         }
         str++;
+
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
             /* NULL at the end of the string */

From 6628ea7ee45a5db84fe06069c8bdd7660ecdb073 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 15:09:18 +0530
Subject: [PATCH 21/23] gh-127740: Check if we had a second digit

---
 Objects/bytesobject.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 474a625143e9a7..533089d25cd73a 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2543,8 +2543,8 @@ _PyBytes_FromHex(PyObject *string, int use_bytearray)
 
         bot = _PyLong_DigitValue[*str];
         if (bot >= 16) {
-            /* NULL at the end of the string */
-            if (bot == 37){
+            /* Check if we had a second digit */
+            if (str >= end){
                 invalid_char = -1;
             } else {
                 invalid_char = str - PyUnicode_1BYTE_DATA(string);

From b20e248f2b8bfe524b8b2d4a2a4a8dd4180c3818 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 21:09:41 +0530
Subject: [PATCH 22/23] Add News entry

---
 .../2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst             | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst
new file mode 100644
index 00000000000000..cf175dfcd21893
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst
@@ -0,0 +1,3 @@
+Fix error message in :func:`bytes.fromhex()` when given an odd number of
+digits to properly indicate that an even number of hexadecimal digits is
+required.

From cbf50b438ffc02c75231182135b1c17bef7b18a0 Mon Sep 17 00:00:00 2001
From: Srinivas Reddy Thatiparthy <thatiparthysreenivas@gmail.com>
Date: Tue, 10 Dec 2024 22:01:48 +0530
Subject: [PATCH 23/23] Fix lint

---
 .../2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst              | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst
index cf175dfcd21893..f614dbb59bdc87 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-12-10-21-08-05.gh-issue-127740.0tWC9h.rst
@@ -1,3 +1,3 @@
-Fix error message in :func:`bytes.fromhex()` when given an odd number of
+Fix error message in :func:`bytes.fromhex` when given an odd number of
 digits to properly indicate that an even number of hexadecimal digits is
 required.