Avoid unnecessary use of strncpy in a couple of places in ecpg.

Use of strncpy with a length limit based on the source, rather than
the destination, is non-idiomatic and draws warnings from gcc 8.
Replace with memcpy, which does exactly the same thing in these cases,
but with less chance for confusion.

Backpatch to all supported branches.

Discussion: https://postgr.es/m/21789.1529170195@sss.pgh.pa.us

diff --git a/src/interfaces/ecpg/ecpglib/descriptor.c b/src/interfaces/ecpg/ecpglib/descriptor.c
index 15fd7a08a53108102a45fc2dc9dd50a54e96fa12..899656107833731a203b873f490adbbdb815a511 100644 (file)
--- a/src/interfaces/ecpg/ecpglib/descriptor.c
+++ b/src/interfaces/ecpg/ecpglib/descriptor.c
@@ -217,7 +217,7 @@ get_char_item(int lineno, void *var, enum ECPGttype vartype, char *value, int va
                                (struct ECPGgeneric_varchar *) var;
 
                                if (varcharsize == 0)
-                                       strncpy(variable->arr, value, strlen(value));
+                                       memcpy(variable->arr, value, strlen(value));
                                else
                                        strncpy(variable->arr, value, varcharsize);
 

diff --git a/src/interfaces/ecpg/pgtypeslib/common.c b/src/interfaces/ecpg/pgtypeslib/common.c
index 9084fd06b4e051c93d816f903b900a538465200d..fd29e30a3bbb3be6ed49150672f0c39781a2a700 100644 (file)
--- a/src/interfaces/ecpg/pgtypeslib/common.c
+++ b/src/interfaces/ecpg/pgtypeslib/common.c
@@ -42,10 +42,8 @@ pgtypes_fmt_replace(union un_fmt_comb replace_val, int replace_type, char **outp
                        i = strlen(replace_val.str_val);
                        if (i + 1 <= *pstr_len)
                        {
-                               /*
-                                * copy over i + 1 bytes, that includes the tailing terminator
-                                */
-                               strncpy(*output, replace_val.str_val, i + 1);
+                               /* include trailing terminator in what we copy */
+                               memcpy(*output, replace_val.str_val, i + 1);
                                *pstr_len -= i;
                                *output += i;
                                if (replace_type == PGTYPES_TYPE_STRING_MALLOCED)