Commit: patch 9.1.1691: over-allocation in ga_concat_strings()

[Christian Brabandt]

patch 9.1.1691: over-allocation in ga_concat_strings()

Commit: https://github.com/vim/vim/commit/0a9ad34cad8e104dd8eaf4c45af007bf049104e0
Author: Damien Lejay <dam...@lejay.be>
Date: Tue Aug 26 17:55:14 2025 +0200

patch 9.1.1691: over-allocation in ga_concat_strings()

Problem: over-allocation in ga_concat_strings()
Solution: Fix ga_concat_strings() and only allocate n-1 separator length
bytes (Damien Lejay).

ga_concat_strings() was adding the separator length for every item,
including the last one. Only (n - 1) separators are actually used.
This caused harmless but unnecessary overallocation.

closes: #18112

Signed-off-by: Damien Lejay <dam...@lejay.be>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/alloc.c b/src/alloc.c
index 5f39085bc..386964c5b 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -770,7 +770,10 @@ ga_concat_strings(garray_T *gap, char *sep)
char_u *p;

for (i = 0; i < gap->ga_len; ++i)
- len += (int)STRLEN(((char_u **)(gap->ga_data))[i]) + sep_len;
+ len += (int)STRLEN(((char_u **)(gap->ga_data))[i]);
+
+ if (gap->ga_len > 1)
+ len += (gap->ga_len - 1) * sep_len;

s = alloc(len + 1);
if (s == NULL)
diff --git a/src/version.c b/src/version.c
index b0ce4f311..db3a4b7ac 100644
--- a/src/version.c
+++ b/src/version.c
@@ -724,6 +724,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 1691,
/**/
1690,
/**/