port FindProcess to Uninstallers since apparently that's a thing you have to do in NSIS

src/nsis/FindProcess.nsh

@@ -11,13 +11,126 @@
  
 !ifndef FindProcess
 !define FindProcess         '!insertmacro FindProcess'
+
+!ifndef un.FindProcess
+!define un.FindProcess         '!insertmacro un.FindProcess'
  
 !macro FindProcess ProcessList BoolReturn
     Push '${ProcessList}'
     Call FindProcess
     Pop ${BoolReturn}
 !macroend
+
+!macro un.FindProcess ProcessList BoolReturn
+    Push '${ProcessList}'
+    Call un.FindProcess
+    Pop ${BoolReturn}
+!macroend
  
+Function un.FindProcess
+  # return True if any process in ProcessList is active
+  Exch $0     ; get ProcessList, save $0
+  Push $1
+  Push $2
+  Push $R0
+  Push $R1
+  Push $R2
+ 
+  StrCpy $2 "$0,"                 ; $2 = ProcessList
+ 
+  Push 0                          ; set return value = False
+ 
+  # method based upon one by Phoenix1701@gmail.com  1/27/07
+ 
+  System::Alloc 1024
+  Pop $R0                         ; process list buffer
+ 
+  # get an array of all process ids
+  System::Call "Psapi::EnumProcesses(i R0, i 1024, *i .R1)i .r0"
+  ${Unless} $0 = 0
+ 
+      IntOp $R1 $R1 / 4           ; Divide by sizeof(DWORD) to get $R1 process count
+      IntOp $R1 $R1 - 1           ; decr for 0 base loop
+ 
+      ClearErrors
+      ${For} $R2 0 $R1
+          # get a PID from the array
+          IntOp $0 $R2 << 2
+          IntOp $0 $0 + $R0           ; buffer.dword[i]
+          System::Call "*$0(i .r0)"   ; Get next PID
+ 
+          ${Unless} $0 = 0
+              Push $0
+              Call un.GetProcessName
+              Pop $1
+ 
+              # is this process one we are looking for?
+              ${WordFind} '$2' ',' 'E/$1' $0
+              ${Unless} ${Errors}
+                  # yes, change return value
+                  Pop $0          ; discard old result
+                  Push 1          ; set return True
+ 
+                  # exit the loop
+                  ${Break}
+              ${EndUnless}
+          ${EndUnless}
+      ${Next}
+ 
+  ${EndUnless}
+ 
+  System::Free $R0
+ 
+  Pop $0              ; get return value
+  Pop $R2             ; restore registers
+  Pop $R1
+  Pop $R0
+  Pop $2
+  Pop $1
+  Exch $0
+FunctionEnd
+ 
+Function un.GetProcessName
+  # ( Pid -- ProcessName )
+  Exch $2                     ; get Pid, save $2
+  Push $0
+  Push $1
+  Push $3
+  Push $R0
+ 
+  System::Call "Kernel32::OpenProcess(i 1040, i 0, i r2)i .r3"
+ 
+  StrCpy $2 "<unknown>"       ; set return value
+ 
+  ${Unless} $3 = 0            ; $3 is hProcess
+      # get hMod array
+      System::Alloc 1024
+      Pop $R0
+ 
+      # params: Pid, &hMod, sizeof(hMod), &cb
+      System::Call "Psapi::EnumProcessModules(i r3, i R0, i 1024, *i .r1)i .r0"
+ 
+      ${Unless} $0 = 0
+          # get first hMod
+          System::Call "*$R0(i .r0)"
+ 
+          # get BaseName; params: Pid, hMod, szBuffer, sizeof(szBuffer)
+          System::Call "Psapi::GetModuleBaseName(i r3, i r0, t .r2, i 256)i .r0"
+      ${EndUnless}
+ 
+      System::Free $R0
+      System::Call "kernel32::CloseHandle(i r3)"
+  ${EndUnless}
+ 
+  Pop $R0                     ; restore registers
+  Pop $3
+  Pop $1
+  Pop $0
+  Exch $2                     ; save process name
+FunctionEnd
+!endif
+
+
 Function FindProcess
   # return True if any process in ProcessList is active
   Exch $0     ; get ProcessList, save $0
@@ -119,4 +232,4 @@ Function GetProcessName
   Pop $0
   Exch $2                     ; save process name
 FunctionEnd
-!endif
+!endif

src/nsis/i2pbrowser-installer.nsi

@@ -224,11 +224,11 @@ SectionEnd
 # uninstaller section start
 Section "uninstall"
     # Don't try to uninstall until the router is fully shut down.
-    ${FindProcess} "I2P.exe" $0
+    ${un.FindProcess} "I2P.exe" $0
     ${If} $0 <> 0
         MessageBox MB_OK "I2P is still running, uninstaller is paused. Uninstaller will continue after I2P has shut down."
         ${Do}
-            ${FindProcess} "I2P.exe" $0
+            ${un.FindProcess} "I2P.exe" $0
             Sleep 500
         ${LoopWhile} $0 <> 0
     ${EndIf}