1 files changed, 21 insertions, 39 deletions

diff --git a/src/nvim/charset.c b/src/nvim/charset.c
index f824717fcd..7b307b8160 100644
--- a/src/nvim/charset.c
+++ b/src/nvim/charset.c
@@ -1620,13 +1620,16 @@ bool vim_isblankline(char_u *lbuf)
 /// @param maxlen Max length of string to check.
 void vim_str2nr(const char_u *const start, int *const prep, int *const len,
                 const int what, varnumber_T *const nptr,
-                uvarnumber_T *const unptr, const int maxlen)
+                uvarnumber_T *const unptr, int maxlen)
   FUNC_ATTR_NONNULL_ARG(1)
 {
-  const char_u *ptr = start;
+  const char *ptr = (const char *)start;
+  if (maxlen == 0) {
+    maxlen = (int)strlen(ptr);
+  }
+  const char *const e = ptr + maxlen;
   int pre = 0;  // default is decimal
   bool negative = false;
-  uvarnumber_T un = 0;
 
   if (ptr[0] == '-') {
     negative = true;
@@ -1635,19 +1638,19 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
 
   // Recognize hex, octal and bin.
   if ((what & (STR2NR_HEX|STR2NR_OCT|STR2NR_BIN))
-      && (maxlen == 0 || maxlen > 1)
-      && (ptr[0] == '0') && (ptr[1] != '8') && (ptr[1] != '9')) {
+      && maxlen > 1
+      && ptr[0] == '0' && ptr[1] != '8' && ptr[1] != '9') {
     pre = ptr[1];
 
     if ((what & STR2NR_HEX)
-        && (maxlen == 0 || maxlen > 2)
-        && ((pre == 'X') || (pre == 'x'))
+        && maxlen > 2
+        && (pre == 'X' || pre == 'x')
         && ascii_isxdigit(ptr[2])) {
       // hexadecimal
       ptr += 2;
     } else if ((what & STR2NR_BIN)
-               && (maxlen == 0 || maxlen > 2)
-               && ((pre == 'B') || (pre == 'b'))
+               && maxlen > 2
+               && (pre == 'B' || pre == 'b')
                && ascii_isbdigit(ptr[2])) {
       // binary
       ptr += 2;
@@ -1657,32 +1660,26 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
 
       if (what & STR2NR_OCT) {
         // Don't interpret "0", "08" or "0129" as octal.
-        for (int n = 1; ascii_isdigit(ptr[n]); ++n) {
-          if (ptr[n] > '7') {
+        for (int i = 1; i < maxlen && ascii_isdigit(ptr[i]); i++) {
+          if (ptr[i] > '7') {
             // can't be octal
             pre = 0;
             break;
           }
-          if (ptr[n] >= '0') {
+          if (ptr[i] >= '0') {
             // assume octal
             pre = '0';
           }
-          if (n == maxlen) {
-            break;
-          }
         }
       }
     }
   }
 
   // Do the string-to-numeric conversion "manually" to avoid sscanf quirks.
-  int n = 1;
+  uvarnumber_T un = 0;
   if (pre == 'B' || pre == 'b' || what == (STR2NR_BIN|STR2NR_FORCE)) {
     // bin
-    if (pre != 0) {
-      n += 2;  // skip over "0b"
-    }
-    while ('0' <= *ptr && *ptr <= '1') {
+    while (ptr < e && '0' <= *ptr && *ptr <= '1') {
       // avoid ubsan error for overflow
       if (un < UVARNUMBER_MAX / 2) {
         un = 2 * un + (uvarnumber_T)(*ptr - '0');
@@ -1690,13 +1687,10 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
         un = UVARNUMBER_MAX;
       }
       ptr++;
-      if (n++ == maxlen) {
-        break;
-      }
     }
   } else if (pre == '0' || what == (STR2NR_OCT|STR2NR_FORCE)) {
     // octal
-    while ('0' <= *ptr && *ptr <= '7') {
+    while (ptr < e && '0' <= *ptr && *ptr <= '7') {
       // avoid ubsan error for overflow
       if (un < UVARNUMBER_MAX / 8) {
         un = 8 * un + (uvarnumber_T)(*ptr - '0');
@@ -1704,16 +1698,10 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
         un = UVARNUMBER_MAX;
       }
       ptr++;
-      if (n++ == maxlen) {
-        break;
-      }
     }
   } else if (pre == 'X' || pre == 'x' || what == (STR2NR_HEX|STR2NR_FORCE)) {
     // hex
-    if (pre != 0) {
-      n += 2;  // skip over "0x"
-    }
-    while (ascii_isxdigit(*ptr)) {
+    while (ptr < e && ascii_isxdigit(*ptr)) {
       // avoid ubsan error for overflow
       if (un < UVARNUMBER_MAX / 16) {
         un = 16 * un + (uvarnumber_T)hex2nr(*ptr);
@@ -1721,13 +1709,10 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
         un = UVARNUMBER_MAX;
       }
       ptr++;
-      if (n++ == maxlen) {
-        break;
-      }
     }
   } else {
     // decimal
-    while (ascii_isdigit(*ptr)) {
+    while (ptr < e && ascii_isdigit(*ptr)) {
       // avoid ubsan error for overflow
       if (un < UVARNUMBER_MAX / 10) {
         un = 10 * un + (uvarnumber_T)(*ptr - '0');
@@ -1735,9 +1720,6 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
         un = UVARNUMBER_MAX;
       }
       ptr++;
-      if (n++ == maxlen) {
-        break;
-      }
     }
   }
 
@@ -1746,7 +1728,7 @@ void vim_str2nr(const char_u *const start, int *const prep, int *const len,
   }
 
   if (len != NULL) {
-    *len = (int)(ptr - start);
+    *len = (int)(ptr - (const char *)start);
   }
 
   if (nptr != NULL) {