From 95e45f452e69d9f26d541f272106c47806c85bb7 Mon Sep 17 00:00:00 2001
From: Andrew Bettison <andrew@servalproject.org>
Date: Mon, 21 Oct 2013 16:17:33 +1030
Subject: [PATCH] Improve str_to_int() et al

Always set *afterp to point to the first invalid character
even if conversion fails
---
 str.c | 31 ++++++++++++++++---------------
 str.h |  9 +++++----
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/str.c b/str.c
index 11d8d906..7ce43f82 100644
--- a/str.c
+++ b/str.c
@@ -235,11 +235,9 @@ int str_to_int(const char *str, int base, int *result, const char **afterp)
   const char *end = str;
   errno = 0;
   long value = strtol(str, (char**)&end, base);
-  if (errno == ERANGE || end == str || value > INT_MAX || value < INT_MIN)
-    return 0;
   if (afterp)
     *afterp = end;
-  else if (*end)
+  if (errno == ERANGE || end == str || value > INT_MAX || value < INT_MIN || isdigit(*end) || (!afterp && *end))
     return 0;
   if (result)
     *result = value;
@@ -253,11 +251,9 @@ int str_to_uint(const char *str, int base, unsigned *result, const char **afterp
   const char *end = str;
   errno = 0;
   unsigned long value = strtoul(str, (char**)&end, base);
-  if (errno == ERANGE || end == str || value > UINT_MAX)
-    return 0;
   if (afterp)
     *afterp = end;
-  else if (*end)
+  if (errno == ERANGE || end == str || value > UINT_MAX || isdigit(*end) || (!afterp && *end))
     return 0;
   if (result)
     *result = value;
@@ -271,11 +267,9 @@ int str_to_int64(const char *str, int base, int64_t *result, const char **afterp
   const char *end = str;
   errno = 0;
   long long value = strtoll(str, (char**)&end, base);
-  if (errno == ERANGE || end == str)
-    return 0;
   if (afterp)
     *afterp = end;
-  else if (*end)
+  if (errno == ERANGE || end == str || isdigit(*end) || (!afterp && *end))
     return 0;
   if (result)
     *result = value;
@@ -289,11 +283,9 @@ int str_to_uint64(const char *str, int base, uint64_t *result, const char **afte
   const char *end = str;
   errno = 0;
   unsigned long long value = strtoull(str, (char**)&end, base);
-  if (errno == ERANGE || end == str)
-    return 0;
   if (afterp)
     *afterp = end;
-  else if (*end)
+  if (errno == ERANGE || end == str || isdigit(*end) || (!afterp && *end))
     return 0;
   if (result)
     *result = value;
@@ -334,8 +326,11 @@ int str_to_int64_scaled(const char *str, int base, int64_t *result, const char *
 {
   int64_t value;
   const char *end = str;
-  if (!str_to_int64(str, base, &value, &end))
+  if (!str_to_int64(str, base, &value, &end)) {
+    if (afterp)
+      *afterp = end;
     return 0;
+  }
   value *= scale_factor(end, &end);
   if (afterp)
     *afterp = end;
@@ -350,8 +345,11 @@ int str_to_uint64_scaled(const char *str, int base, uint64_t *result, const char
 {
   uint64_t value;
   const char *end = str;
-  if (!str_to_uint64(str, base, &value, &end))
+  if (!str_to_uint64(str, base, &value, &end)) {
+    if (afterp)
+      *afterp = end;
     return 0;
+  }
   value *= scale_factor(end, &end);
   if (afterp)
     *afterp = end;
@@ -386,8 +384,11 @@ int str_to_uint64_interval_ms(const char *str, int64_t *result, const char **aft
     return 0;
   const char *end = str;
   unsigned long long value = strtoull(str, (char**)&end, 10) * precision;
-  if (end == str)
+  if (end == str) {
+    if (afterp)
+      *afterp = end;
     return 0;
+  }
   if (end[0] == '.' && isdigit(end[1])) {
     ++end;
     unsigned factor;
diff --git a/str.h b/str.h
index a2ece4eb..d14b7f47 100644
--- a/str.h
+++ b/str.h
@@ -199,10 +199,11 @@ char *str_str(char *haystack, const char *needle, int haystack_len);
 /* Parse a string as an integer in ASCII radix notation in the given 'base' (eg, base=10 means
  * decimal).
  *
- * Return 1 if a valid integer was parsed, storing the value in *result (unless result is NULL) and
- * storing a pointer to the immediately succeeding character in *afterp (unless afterp is NULL, in
- * which case returns 1 only if the immediately succeeding character is a nul '\0').  Returns 0
- * otherwise, leaving *result and *afterp unchanged.
+ * Returns 1 if a valid integer is parsed, storing the value in *result (unless result is NULL) and
+ * storing a pointer to the immediately succeeding character in *afterp.  If afterp is NULL then
+ * returns 0 unless the immediately succeeding character is a NUL '\0'.  If no integer is parsed or
+ * if the integer overflows (too many digits), then returns 0, leaving *result unchanged and setting
+ * setting *afterp to point to the character where parsing failed.
  *
  * @author Andrew Bettison <andrew@servalproject.com>
  */