D3975: mergetool: warn if ui.merge points to nonexistent tool

[martinvonz (Martin von Zweigbergk)]

martinvonz created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  This adds a warning when ui.merge is configured but points to an
  executable that doesn't exist. It gets printed once per fail, but that
  seems to be how our other warnings about merge tools are reported.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3975

AFFECTED FILES
  mercurial/filemerge.py
  tests/test-merge-tools.t

CHANGE DETAILS

diff --git a/tests/test-merge-tools.t b/tests/test-merge-tools.t
--- a/tests/test-merge-tools.t
+++ b/tests/test-merge-tools.t
@@ -1748,7 +1748,9 @@
   missingbinary.executable=doesnotexist
   # hg update -C 1
   $ hg merge -y -r 2 --config ui.merge=missingbinary
+  couldn't find merge tool missingbinary (for pattern f)
   merging f
+  couldn't find merge tool missingbinary (for pattern f)
   revision 1
   space
   revision 0
diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -208,9 +208,10 @@
     if uimerge:
         # external tools defined in uimerge won't be able to handle
         # change/delete conflicts
-        if uimerge not in names and not changedelete:
-            return (uimerge, uimerge)
-        tools.insert(0, (None, uimerge)) # highest priority
+        if check(uimerge, path, symlink, binary, changedelete):
+            if uimerge not in names and not changedelete:
+                return (uimerge, uimerge)
+            tools.insert(0, (None, uimerge)) # highest priority
     tools.append((None, "hgmerge")) # the old default, if found
     for p, t in tools:
         if check(t, None, symlink, binary, changedelete):



To: martinvonz, #hg-reviewers
Cc: mercurial-devel