From 185ca149b67087dae275f43fa6fec219ad50a405 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Tue, 1 Oct 2024 00:41:52 +0200
Subject: [PATCH] CPLGetValueType(): do not recognize '01' as integer, but as
 string

Fixes https://github.com/Toblerity/Fiona/issues/1454
---
 apps/gdaltransform.cpp              |  5 +++++
 autotest/cpp/test_cpl.cpp           | 15 ++++++++-------
 ogr/ogrsf_frmts/csv/ogrcsvlayer.cpp |  4 +++-
 port/cpl_string.cpp                 |  4 ++++
 4 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/apps/gdaltransform.cpp b/apps/gdaltransform.cpp
index 7dea9f3bbb48..5c835b559bee 100644
--- a/apps/gdaltransform.cpp
+++ b/apps/gdaltransform.cpp
@@ -402,6 +402,11 @@ MAIN_START(argc, argv)
             if (fgets(szLine, sizeof(szLine) - 1, stdin) == nullptr)
                 break;
 
+            size_t nLen = strlen(szLine);
+            if (nLen && szLine[nLen - 1] == '\n')
+                szLine[--nLen] = 0;
+            if (nLen && szLine[nLen - 1] == '\r')
+                szLine[--nLen] = 0;
             const CPLStringList aosTokens(CSLTokenizeString(szLine));
             const int nCount = aosTokens.size();
 
diff --git a/autotest/cpp/test_cpl.cpp b/autotest/cpp/test_cpl.cpp
index 9701f8922cb2..7861eb31da44 100644
--- a/autotest/cpp/test_cpl.cpp
+++ b/autotest/cpp/test_cpl.cpp
@@ -163,7 +163,7 @@ typedef struct
 // Test CPLGetValueType
 TEST_F(test_cpl, CPLGetValueType)
 {
-    TestStringStruct apszTestStrings[] = {
+    TestStringStruct asTestStrings[] = {
         {"+25.e+3", CPL_VALUE_REAL},   {"-25.e-3", CPL_VALUE_REAL},
         {"25.e3", CPL_VALUE_REAL},     {"25e3", CPL_VALUE_REAL},
         {" 25e3 ", CPL_VALUE_REAL},    {".1e3", CPL_VALUE_REAL},
@@ -176,15 +176,16 @@ TEST_F(test_cpl, CPLGetValueType)
         {"25.25.3", CPL_VALUE_STRING}, {"25e25e3", CPL_VALUE_STRING},
         {"25e2500", CPL_VALUE_STRING}, /* #6128 */
 
-        {"d1", CPL_VALUE_STRING} /* #6305 */
+        {"d1", CPL_VALUE_STRING}, /* #6305 */
+
+        {"01", CPL_VALUE_STRING},      {"0.1", CPL_VALUE_REAL},
+        {"0", CPL_VALUE_INTEGER},
     };
 
-    size_t i;
-    for (i = 0; i < sizeof(apszTestStrings) / sizeof(apszTestStrings[0]); i++)
+    for (const auto &sText : asTestStrings)
     {
-        EXPECT_EQ(CPLGetValueType(apszTestStrings[i].testString),
-                  apszTestStrings[i].expectedResult)
-            << apszTestStrings[i].testString;
+        EXPECT_EQ(CPLGetValueType(sText.testString), sText.expectedResult)
+            << sText.testString;
     }
 }
 
diff --git a/ogr/ogrsf_frmts/csv/ogrcsvlayer.cpp b/ogr/ogrsf_frmts/csv/ogrcsvlayer.cpp
index ba3194e5e3ac..98a3a574ef69 100644
--- a/ogr/ogrsf_frmts/csv/ogrcsvlayer.cpp
+++ b/ogr/ogrsf_frmts/csv/ogrcsvlayer.cpp
@@ -2405,7 +2405,9 @@ OGRErr OGRCSVLayer::ICreateFeature(OGRFeature *poNewFeature)
                     pszContent, -1,
                     (m_eStringQuoting == StringQuoting::ALWAYS ||
                      (m_eStringQuoting == StringQuoting::IF_AMBIGUOUS &&
-                      CPLGetValueType(pszContent) != CPL_VALUE_STRING))
+                      (CPLGetValueType(pszContent) != CPL_VALUE_STRING ||
+                       (pszContent[0] == DIGIT_ZERO && pszContent[1] != '\0' &&
+                        pszContent[1] != '.'))))
                         ? CPLES_CSV_FORCE_QUOTING
                         : CPLES_CSV);
             }
diff --git a/port/cpl_string.cpp b/port/cpl_string.cpp
index f7372c29f7cd..06a44ad4d8ed 100644
--- a/port/cpl_string.cpp
+++ b/port/cpl_string.cpp
@@ -2791,6 +2791,10 @@ CPLValueType CPLGetValueType(const char *pszValue)
     if (*pszValue == '+' || *pszValue == '-')
         ++pszValue;
 
+    constexpr char DIGIT_ZERO = '0';
+    if (pszValue[0] == DIGIT_ZERO && pszValue[1] != '\0' && pszValue[1] != '.')
+        return CPL_VALUE_STRING;
+
     bool bFoundDot = false;
     bool bFoundExponent = false;
     bool bIsLastCharExponent = false;