vim-patch:8.2.3139: functions for string manipulation are spread out (#23316)

Problem:    Functions for string manipulation are spread out.
Solution:   Move string related functions to a new source file. (Yegappan
            Lakshmanan, closes vim/vim#8470)

https://github.com/vim/vim/commit/a2438132a675be4dde3acbdf03ba1fdb2f09427c

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index ab787524a9..78204b22a8 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -2361,6 +2361,34 @@ static char *iconv_string(const vimconv_T *const vcp, const char *str, size_t sl
   return result;
 }
 
+/// iconv() function
+void f_iconv(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  vimconv_T vimconv;
+
+  rettv->v_type = VAR_STRING;
+  rettv->vval.v_string = NULL;
+
+  const char *const str = tv_get_string(&argvars[0]);
+  char buf1[NUMBUFLEN];
+  char *const from = enc_canonize(enc_skip((char *)tv_get_string_buf(&argvars[1], buf1)));
+  char buf2[NUMBUFLEN];
+  char *const to = enc_canonize(enc_skip((char *)tv_get_string_buf(&argvars[2], buf2)));
+  vimconv.vc_type = CONV_NONE;
+  convert_setup(&vimconv, from, to);
+
+  // If the encodings are equal, no conversion needed.
+  if (vimconv.vc_type == CONV_NONE) {
+    rettv->vval.v_string = xstrdup(str);
+  } else {
+    rettv->vval.v_string = string_convert(&vimconv, (char *)str, NULL);
+  }
+
+  convert_setup(&vimconv, NULL, NULL);
+  xfree(from);
+  xfree(to);
+}
+
 /// Setup "vcp" for conversion from "from" to "to".
 /// The names must have been made canonical with enc_canonize().
 /// vcp->vc_type must have been initialized to CONV_NONE.