From 1d62df2df0b1b0fcb559247c5c7042f5e673a38b Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Sat, 18 Apr 2020 19:02:35 +0200
Subject: [PATCH] Revert "[SV 54161] Fix second expansion of $* for paths"

This reverts commit 86f2f8bcb5b4a03da8eb37e9a99c22d8fec4bfb2.

This commit breaks secondary expansion in builds of aegisub at very least,
revert to previous behavior for the time being while this is investigated.
---
 src/implicit.c                     | 56 +++++++++---------------------
 tests/scripts/features/se_implicit |  8 -----
 2 files changed, 17 insertions(+), 47 deletions(-)

diff --git a/src/implicit.c b/src/implicit.c
index b281a17..4d0a01f 100644
--- a/src/implicit.c
+++ b/src/implicit.c
@@ -221,9 +221,8 @@ pattern_search (struct file *file, int archive,
   struct patdeps *deplist = xmalloc (max_deps * sizeof (struct patdeps));
   struct patdeps *pat = deplist;
 
-  /* Names of possible dependencies are constructed in this buffer.
-     We may replace % by $(*F) for second expansion, increasing the length.  */
-  char *depname = alloca (namelen + max_pattern_dep_length + 4);
+  /* Names of possible dependencies are constructed in this buffer.  */
+  char *depname = alloca (namelen + max_pattern_dep_length);
 
   /* The start and length of the stem of FILENAME for the current rule.  */
   const char *stem = 0;
@@ -479,10 +478,9 @@ pattern_search (struct file *file, int archive,
                 }
             }
 
-          if (stemlen + (check_lastslash ? pathlen : 0) > GET_PATH_MAX)
+          if (stemlen > GET_PATH_MAX)
             {
-              DBS (DB_IMPLICIT, (_("Stem too long: '%s%.*s'.\n"),
-                                 check_lastslash ? pathdir : "",
+              DBS (DB_IMPLICIT, (_("Stem too long: '%.*s'.\n"),
                                  (int) stemlen, stem));
               continue;
             }
@@ -490,19 +488,8 @@ pattern_search (struct file *file, int archive,
           DBS (DB_IMPLICIT, (_("Trying pattern rule with stem '%.*s'.\n"),
                              (int) stemlen, stem));
 
-          if (!check_lastslash)
-            {
-              memcpy (stem_str, stem, stemlen);
-              stem_str[stemlen] = '\0';
-            }
-          else
-            {
-              /* We want to prepend the directory from
-                 the original FILENAME onto the stem.  */
-              memcpy (stem_str, filename, pathlen);
-              memcpy (stem_str + pathlen, stem, stemlen);
-              stem_str[pathlen + stemlen] = '\0';
-            }
+          strncpy (stem_str, stem, stemlen);
+          stem_str[stemlen] = '\0';
 
           /* If there are no prerequisites, then this rule matches.  */
           if (rule->deps == 0)
@@ -553,7 +540,7 @@ pattern_search (struct file *file, int archive,
                         }
                       memcpy (o, nptr, p - nptr);
                       o += p - nptr;
-                      memcpy (o, stem, stemlen);
+                      memcpy (o, stem_str, stemlen);
                       o += stemlen;
                       strcpy (o, p + 1);
                     }
@@ -605,10 +592,10 @@ pattern_search (struct file *file, int archive,
                      again.  This is not good if you have certain characters
                      in your stem (like $).
 
-                     Instead, we will replace % with $* or $(*F) and allow the
-                     second expansion to take care of it for us.  This way
-                     (since $* and $(*F) are simple variables) there won't be
-                     additional re-expansion of the stem.  */
+                     Instead, we will replace % with $* and allow the second
+                     expansion to take care of it for us.  This way (since $*
+                     is a simple variable) there won't be additional
+                     re-expansion of the stem.  */
 
                   p = lindex (nptr, nptr + len, '%');
                   if (p == 0)
@@ -619,22 +606,13 @@ pattern_search (struct file *file, int archive,
                   else
                     {
                       size_t i = p - nptr;
-                      char *o = depname;
-                      memcpy (o, nptr, i);
-                      o += i;
+                      memcpy (depname, nptr, i);
+                      memcpy (depname + i, "$*", 2);
+                      memcpy (depname + i + 2, p + 1, len - i - 1);
+                      depname[len + 2 - 1] = '\0';
+
                       if (check_lastslash)
-                        {
-                          add_dir = 1;
-                          memcpy (o, "$(*F)", 5);
-                          o += 5;
-                        }
-                      else
-                        {
-                          memcpy (o, "$*", 2);
-                          o += 2;
-                        }
-                      memcpy (o, p + 1, len - i - 1);
-                      o[len - i - 1] = '\0';
+                        add_dir = 1;
                     }
 
                   /* Set up for the next word.  */
diff --git a/tests/scripts/features/se_implicit b/tests/scripts/features/se_implicit
index 866d1fb..a01b385 100644
--- a/tests/scripts/features/se_implicit
+++ b/tests/scripts/features/se_implicit
@@ -254,13 +254,5 @@ foo: $$(info $$<)
 !,
               '', "bar\n#MAKE#: Nothing to be done for 'foo'.\n");
 
-# SV 54161: Expand $$* properly when it contains a path
-
-run_make_test(q!
-.SECONDEXPANSION:
-%x: $$(info $$*); @echo '$*'
-!,
-              'q/ux', "q/u\nq/u\n");
-
 # This tells the test driver that the perl test script executed properly.
 1;
-- 
2.26.1